Programas escolares de actividad física para promover la actividad física y la buena forma física en niños y adolescentes de entre seis y 18 años de edad
Resumen
Antecedentes
La actividad física entre los niños y los adolescentes se asocia con una menor adiposidad, una mejor salud cardiometabólica y una mejor forma física. En todo el mundo, menos del 30% de los niños y adolescentes cumplen las recomendaciones mundiales de actividad física de al menos 60 minutos de actividad física moderada a intensa al día. Las escuelas podrían ser lugares ideales para las intervenciones, dado que los niños y adolescentes en la mayoría de sitios del mundo pasan una cantidad considerable de tiempo en el trayecto a la escuela o asistiendo a ella.
Objetivos
El propósito de esta actualización de la revisión es resumir la evidencia sobre la efectividad de las intervenciones escolares para aumentar la actividad física moderada a intensa y mejorar la forma física en niños y adolescentes de seis a 18 años de edad.
Los objetivos específicos son:
• evaluar los efectos de las intervenciones escolares en el aumento de la actividad física y la mejora de la forma física de niños y adolescentes;
• evaluar los efectos de las intervenciones escolares sobre la composición corporal; y
• determinar si ciertas combinaciones o componentes (o ambos) de las intervenciones escolares son más efectivos que otros para promover la actividad física y la buena forma física en esta población destinataria.
Métodos de búsqueda
Se realizaron búsquedas en CENTRAL, MEDLINE, Embase, CINAHL y PsycINFO, BIOSIS, SPORTDiscus y Sociological Abstracts hasta el 1 de junio de 2020, sin restricciones de idioma. Se examinaron listas de referencias de los artículos incluidos y las revisiones sistemáticas relevantes. Se estableció contacto con los autores principales de los estudios para obtener información adicional.
Criterios de selección
Las intervenciones elegibles fueron aquellas relevantes para la práctica de la salud pública (es decir, no realizadas en ámbitos clínicos), se implementaron en el contexto escolar y tuvieron como objetivo aumentar la actividad física de todos los niños y adolescentes que asisten a la escuela (de seis a 18 años) durante al menos 12 semanas. La revisión se limitó a los ensayos controlados aleatorizados. En esta actualización se han añadido dos nuevos criterios: que el objetivo principal del estudio fuera aumentar la actividad física o la forma física, y que el estudio utilizara una medida objetiva de la actividad física o la forma física. Los desenlaces principales incluyeron la proporción de participantes que cumplieron las recomendaciones de actividad física y la duración de la actividad física moderada a intensa y del tiempo de sedentarismo (nuevo en esta actualización). Los desenlaces secundarios incluyeron índice de masa corporal (IMC) medido, forma física, calidad de vida relacionada con la salud (nuevo en esta actualización) y eventos adversos (nuevo en esta actualización). El tiempo dedicado a ver televisión, el colesterol en sangre y la presión arterial se han eliminado de esta actualización.
Obtención y análisis de los datos
Dos autores de la revisión independientes utilizaron instrumentos normalizados para evaluar la relevancia de cada estudio, extraer los datos y evaluar el riesgo de sesgo. Se discutieron las discrepancias que surgieron hasta que se alcanzó un consenso. La certeza de la evidencia se evaluó con el método GRADE. Cuando se presentaron datos suficientes se realizó un metanálisis de efectos aleatorios basado en el método de la varianza inversa con los participantes estratificados por edad (niños versus adolescentes). Los efectos por tipo de intervención se exploraron mediante análisis de subgrupos.
Resultados principales
Siguiendo los tres nuevos criterios de inclusión, se excluyeron 16 de los 44 estudios incluidos en la anterior versión de esta revisión. Se examinaron otros 9968 títulos (búsqueda de octubre de 2011 a junio de 2020), de los cuales 978 estudios únicos fueron potencialmente pertinentes y 61 cumplieron todos los criterios de esta actualización. Esta actualización incluye 89 estudios que representan los datos completos de 66 752 participantes de los estudios. La mayoría de los estudios incluyeron solo niños (n = 56), seguidos de solo adolescentes (n = 22), y ambos (n = 10); un estudio no informó sobre la edad de los estudiantes. Las intervenciones con varios componentes fueron las más frecuentes (n = 40), seguidas de la actividad física en la escuela (n = 19), la educación física mejorada (n = 15) y los programas extraescolares (n = 14); un estudio exploró tanto la educación física mejorada como un programa extraescolar. La ausencia de cegamiento de los participantes, del personal y de los evaluadores de desenlaces, así como las pérdidas de contacto con los participantes fueron las fuentes de sesgo más habituales.
Los resultados muestran que las intervenciones de actividad física en la escuela probablemente producen un aumento escaso o nulo del tiempo dedicado a la actividad física moderada a intensa (diferencia de medias [DM] 0,73 minutos/d; intervalo de confianza [IC] del 95%: 0,16 a 1,30; 33 estudios; evidencia de certeza moderada) y podrían conllevar una disminución escasa o nula del tiempo de sedentarismo (DM ‐3,78 minutos/d; IC del 95%: ‐7,80 a 0,24; 16 estudios; evidencia de certeza baja). Las intervenciones de actividad física en la escuela podrían mejorar la forma física representada como el consumo máximo de oxígeno (VO₂max) (DM 1,19 ml/kg/min; IC del 95%: 0,57 a 1,82; 13 estudios; evidencia de certeza baja). Las intervenciones de actividad física en la escuela podrían suponer una disminución muy pequeña en las puntuaciones del IMC (DM ‐0,06; IC del 95%: ‐0,09 a ‐0,02; 21 estudios; evidencia de certeza baja) y podrían no tener efectos en el IMC expresado en kg/m² (DM ‐0,07; IC del 95%: ‐0,15 a 0,01; 50 estudios; evidencia de certeza baja). Se desconoce el efecto de las intervenciones escolares de actividad física sobre la calidad de vida relacionada con la salud o sobre los eventos adversos.
Conclusiones de los autores
Dada la variabilidad de los resultados y los ligeros efectos generales, el personal escolar y los profesionales de la salud pública deben reflexionar mucho sobre este asunto antes de poner en marcha intervenciones de actividad física en la escuela. Dada la heterogeneidad de los efectos, el riesgo de sesgo y los hallazgos de que la magnitud del efecto es generalmente pequeña, estos resultados deberían interpretarse con precaución.
PICO
Resumen en términos sencillos
¿Las intervenciones escolares de actividad física aumentan la actividad física moderada a intensa y mejoran la forma física de niños y adolescentes?
Mensajes clave
Las intervenciones escolares podrían mejorar la forma física, pero podrían tener poco o ningún efecto en el índice de masa corporal (que se utiliza para evaluar si el peso corporal está en una franja saludable), aunque no se tiene confianza en la evidencia.
Muy pocos estudios informaron de posibles efectos perjudiciales.
Se debe considerar cuidadosamente el tipo de programa escolar de actividad física que debe aplicarse, y los estudios futuros deben tratar de identificar los mejores tipos de intervenciones de actividad física para entornos escolares.
¿Por qué es importante promover la actividad física en los niños?
Se estima que hasta 5 300 000 muertes en el mundo están causadas por la falta de ejercicio (inactividad física), además de tratarse de un gran factor de riesgo clave en la aparición de la mayoría de enfermedades crónicas y cánceres. Estos datos son preocupantes, particularmente porque se sabe que los hábitos de actividad física de la infancia pueden conllevar hábitos similares en la edad adulta. Se cree que los programas que animan a los niños a hacer ejercicio en la escuela son una forma de aumentar los niveles de actividad de todos los niños, independientemente de otros factores como la conducta de los padres y los factores socioeconómicos de los primeros años de vida del niño.
¿Qué se encontró?
Se hallaron 89 estudios que observaron los efectos de los programas escolares centrados en aumentar la actividad física e incluyeron 66 752 niños y adolescentes (de entre seis y 18 años) de todo el mundo. La duración del programa varió de 12 semanas a seis años. No hubo dos programas escolares de actividades físicas que utilizaran la misma combinación de intervenciones. La frecuencia y la duración de cada parte del programa variaron mucho entre los estudios.
En todos los estudios incluidos, sólo se observaron cambios muy pequeños en el número de estudiantes que realizaron actividad física o en los minutos diarios de actividad física moderada a intensa o en el tiempo de sedentarismo, aunque se comprobó que estos programas mejoraban la forma física de los estudiantes. Se ha observado que estos programas tienen poca o ninguna repercusión en las mediciones utilizadas para evaluar si el peso corporal se encuentra en una franja saludable. Pocos estudios comunicaron posibles efectos perjudiciales, como las lesiones o el daño psicológico.
¿Cuáles son las limitaciones de la evidencia?
Existe poca confianza en la evidencia porque los estudios se hicieron de diferentes maneras y las intervenciones se administraron y evaluaron de diferentes formas. Además, es posible que los participantes de los estudios supieran qué intervenciones estaban recibiendo, lo que a veces puede afectar los efectos comunicados. Además, no todos los estudios proporcionaron datos sobre todo lo que interesaba en esta revisión.
¿Cuál es el grado de actualización de esta evidencia?
La evidencia está actualizada hasta junio de 2020 (aunque se realizó una nueva búsqueda de estudios en febrero de 2021 y se encontraron estudios que podrían incluirse en una futura actualización y que ahora se describen en la tabla "Estudios pendientes de clasificación").
Authors' conclusions
Summary of findings
| School‐based physical activity programmes for promoting physical activity and fitness in children and adolescents aged 6 to 18 years | ||||
| Population: children and adolescents aged 6 to 18 years Settings: primarily within the school setting Intervention: educational, health promotion, counselling, and management strategies focused on promotion of physical activity and fitness Comparison: standard, currently existing physical education programmes in schools | ||||
| Outcomes | Anticipated effects (95% CI) | No. of participants | Certainty of the evidence | |
|---|---|---|---|---|
| Risk with control | Risk with intervention | |||
| % of participants physically active [follow‐up: 12 weeks to 12 months] | % physically active ranged from 2% to 50% | % physically active ranged from 1.11% lower to 12.22% higher. | 6,068 (5) | ⊕⊝⊝⊝ very lowa |
| Moderate to vigorous physical activity (minutes/d) [follow‐up: 12 weeks to 3 years] | ‐3.63 (‐5.03 to ‐2.23) | MD 0.73, 95% CI 0.16 to 1.30 | 20,614 (33) | ⊕⊕⊕⊝ moderateb |
| Sedentary time (minutes/d) | 27.77 (‐21.34 to 76.88) | MD ‐3.78, 95% CI ‐7.80 to 0.24 | 11,914 (16) | ⊕⊕⊝⊝ lowc |
| Physical fitness (VO₂ max, mL/kg/min) | ‐1.00 (‐1.59 to ‐0.41) | MD 1.19, 95% CI 0.57 to 1.82 | 3,980 (13) | ⊕⊕⊝⊝ lowd |
| BMI (z‐score) | ‐0.01 (‐0.08 to 0.06) | MD ‐0.06, 95% CI ‐0.09 to ‐0.02 | 22,948 (21) | ⊕⊕⊝⊝ lowe |
| BMI (kg/m²) | ‐0.35 (‐1.06 to 0.36) | MD ‐0.07, 95% CI ‐0.15 to 0.01 | 34,337 (50) | |
| Health‐related quality of life [follow‐up: 15 weeks to 12 months] | Not estimable; insufficient data reported within studies | 4,687 (7) | ⊕⊝⊝⊝ very lowf | |
| Adverse events [follow‐up: 12 weeks to 3 years] | Not estimable; only 3 studies reported any adverse events | 11,698 (16) | ⊕⊝⊝⊝ very lowg | |
| BMI: body mass index; CI: confidence interval; MD: mean difference; min/d: minutes per day; VO₂max: maximal oxygen uptake. | ||||
| GRADE Working Group grades of evidence. | ||||
| aDowngraded by one level each for inconsistency (large variation in effects across studies), imprecision (wide confidence intervals), and risk of bias (high or unclear in most studies). bDowngraded by one level for inconsistency (visual inspection of forest plots and I² value from meta‐analysis). cDowngraded by one level for imprecision of results (wide confidence intervals) and risk of bias (high or unclear in many studies). dDowngraded by one level for inconsistency (visual inspection of forest plots and I² value from meta‐analysis) and indirectness (estimated vs measured VO₂ peak). eDowngraded by one level for inconsistency (visual inspection of forest plots and I² value from meta‐analysis), risk of bias (high or unclear in most studies). fDowngraded by one level for inconsistency (large variation across studies), risk of bias (high or unclear in most studies), publication bias (most studies not reporting on health‐related quality of life or describing full results). gDowngraded by one level for inconsistency (large variation across studies), publication bias (most studies not reporting on adverse events or methods for monitoring), risk of bias (high or unclear in most studies). | ||||
Background
Description of the condition
International public health and health promotion organisations have identified health risks across the lifespan associated with physical inactivity. Recent estimates suggest that 5.3 million deaths per year throughout the world are attributable to physical inactivity (Lee 2012a). Globally, physical inactivity has been identified as the fourth leading risk factor for global mortality (6% of all deaths), following high blood pressure, tobacco use, and high blood glucose, and overweight and obesity are responsible for 5% of deaths globally (Warburton 2017; WHO 2008). Physical inactivity is estimated to cause 10% of the burden of disease from breast cancer and colon cancer, as well as 7% from type 2 diabetes, and 6% from coronary heart disease (Lee 2012a). The burden of these and other chronic diseases has rapidly increased in recent decades (WHO 2008). In fact, physical activity was labelled as “today's best buy in public health” almost three decades ago (Morris 1994). Recent estimates suggest that physical inactivity cost healthcare systems $ (INT$) 53.8 billion worldwide in 2013 (Ding Ding 2016). In addition, the literature indicates that an elevated body mass index (BMI) places children and adolescents at greater risk for cardiovascular disease as adults, and that diet and physical activity are important factors in maintaining a healthy BMI range (Hills 2011). Longitudinal data have shown that for each weekday that adolescents of normal weight participated in physical education (PE), the odds of becoming overweight in adulthood decreased by 5% (Menschik 2008).
Previous reports have concluded that the intensity, frequency, and duration of physical activity contribute to overall physical health status and suggest that a 'threshold' must be maintained to produce positive health effects (CDC 1999; Shephard 1997; Tolfrey 2000). In fact, a positive linear association between duration of physical activity and positive health effects has been established, with longer duration associated with improved physical health (Carson 2017; Janssen 2010; Shephard 1997). Maximal oxygen uptake (VO₂max) is a standard measure associated with fitness levels, with increasing values expected as fitness level improves, and is an important indicator of successful physical activity interventions. Recent analyses have shown a dose‐response relationship between physical activity behaviours (minutes/week of moderate to vigorous physical activity (MVPA)) and fitness levels (measured by VO₂max) and measures of cardio‐metabolic health, including measures of body composition, blood pressure, and blood cholesterol (Nevill 2020; Sriram 2021).
Current guidelines suggest that children and adolescents should engage in at least 60 minutes of MVPA per day, along with muscle and bone strengthening activities at least 3 days per week (Chaput 2020). Examples of moderate to vigorous activities include brisk walking, jogging, stair climbing, basketball, racquet sports, soccer, dance, lap swimming, skating, strength training, cross‐country skiing, and cycling. In the most recently released global physical activity guidelines, evidence suggests that time spent in sedentary behaviour is associated with poorer health outcomes in both children and adolescents, and it is recommended that children and adolescents limit sedentary time, especially when sedentary time is combined with recreational screen time (Chaput 2020). Research suggests that the best primary strategy for improving the long‐term health of children and adolescents through exercise may involve creating a lifestyle pattern of regular MVPA that will carry over to the adult years (Freedson 1992; Telama 2005; Twisk 2000). Despite this, the Global Matrix 3.0 Physical Activity Report Card Grades for Children and Youth on physical levels of children and youth from 49 countries revealed a mean letter grade of C for the percentage of children and youth meeting the physical activity recommendation of 60 minutes of MVPA per day, representing 27% to 33% of children and youth (Aubert 2018). Therefore it is of primary importance to identify approaches that will be effective in increasing and sustaining activity levels of children and adolescents in places where they spend long periods of time, such as schools.
Description of the intervention
To ensure sustained progress towards major improvements in chronic disease prevention, the World Health Organization (WHO) has called on public health organisations within and between countries to work collaboratively with key partners, including educators and health professional bodies, educational institutions, consumer groups, researchers, and the private sector, to provide a comprehensive strategy to promote physical activity among children and adolescents (WHO 2008). The school setting is an ideal environment for population‐based physical activity interventions, as no other institution has as much influence on children during their first two decades of life (Naylor 2009; Story 2009). Recognising the unique opportunity that exists to formulate and implement an effective strategy to substantially reduce deaths and disease burden worldwide by improving diet and promoting physical activity, the WHO has adopted the Health Promoting School (HPS) framework to promote healthy living, learning, and working conditions. An HPS encourages moving beyond individual behaviour change and considering and addressing the whole‐school environment (IUHPE 2010). The WHO specifically identified schools as a target setting for promotion of physical activity among children and youth and suggested that schools implement opportunities and programming for physical activity and provide safe and appropriate spaces that facilitate participation in physical activity (WHO 2008).
Schools are considered an ideal setting for promoting physical activity among children due to their broad reach and multiple opportunities to promote physical activity over the course of the school week, including physical education classes, before and after school programmes, recess programming, active school travel, and classroom‐based physical activity (Singh 2017; Watson 2017a). To effectively promote MVPA, the Centers for Disease Control and Prevention suggests that schools engage in comprehensive approaches to develop, implement, and evaluate physical activity policies and practices; establish school environments that support physical activity; implement a quality physical activity programme with quality physical education as a cornerstone; implement health education that provides students with the knowledge, attitudes, and skills needed for physical activity; provide students with health, mental health, and social services to promote physical activity and prevent chronic disease; partner with families and community members in development and implementation of physical activity policies; provide a school employee wellness programme that includes physical activity services for all school staff members; and employ qualified persons and provide professional development opportunities for physical education and physical activity (CDC 2011).
Studies conducted to date have generally utilised different combinations of physical activity promotion interventions in schools, including before and after school programmes, multi‐component physical activity interventions, enhanced PE, and schooltime physical activity, such as physically active lessons. Generally, interventions focused on providing students with information about the benefits of physical activity and healthy nutrition, the risks associated with inactivity and unhealthy food choices, and the importance of increasing the amount of time students were engaged in MVPA during the school day, as well as ensuring that they expend greater amounts of energy during physical activity sessions. Interventions targeted the school curriculum (related to PE classes specifically and to the whole curriculum generally), teacher training, educational materials, changes in the format of the school day, and accessibility to exercise equipment. Interventions included training sessions for teachers (to learn more effective ways to promote physical activity and to incorporate it into curricula) and training materials including kits, packages of materials to be used in curricula, and materials to be given to students and parents. Packages included teaching notes on exercise, how the body works, and healthy eating and nutrition. Interventions also targeted PE classes by increasing the level of activity students engaged in during these classes, introducing activities geared to the age and level of development of the child, and putting greater emphasis on games. Students were encouraged to be more active outside of school during leisure time. The curriculum focused on creating a positive self‐image through awareness of physical activity benefits. Curriculum changes were implemented in other courses as well, such as science courses, which incorporated discussions of healthy eating and physical activity. Some interventions included changes in the food provided in school cafeterias, so as to increase the number of healthy food choices. Other strategies included a risk factor assessment of students to identify students with established risk factors and development of a plan to reduce student risk through increased physical activity, healthy nutrition, and goal attainment.
How the intervention might work
Given that school‐aged children spend a significant amount of their wakeful time in transit to or in the school setting, and that almost all children in many countries attend school until they reach adolescence, school‐based physical activity promotion interventions have the potential to reduce population‐wide chronic disease (Macnab 2014). In fact, several published systematic reviews have highlighted the benefits of physical activity among healthy children (Brown 2009; Cesa 2014; Granger 2017; Janssen 2010; Kriemler 2011a; Marker 2016; Poitras 2016). School‐based interventions can target simultaneously children at risk and children not at risk for future chronic disease and can increase both knowledge and behaviour conducive to healthier lifestyles. School‐based strategies targeting all students through curriculum ensure that 100% of students are exposed to the intervention, thereby increasing the reach of these interventions. Increased physical activity is an essential public health and health promotion strategy to improve child health (WHO 2008).
The intent of school‐based physical activity interventions is to increase the overall percentage of children and adolescents engaged in MVPA each day while increasing the duration of MVPA engaged in on a weekly basis. The aim of these interventions is to create a school environment that is conducive to achieving a greater proportion of children and adolescents who meet physical activity guidelines, while increasing time spent engaged in MVPA. Generally, this means that significant changes to the school curriculum are needed to support increased time for physical activity as well as increased levels of activity during this time. School‐based interventions offer an important opportunity to improve knowledge of how to prevent non‐communicable disease, and to provide both knowledge about the importance of physical activity and the opportunity for students to be more active before, during, and after school hours, thereby helping them develop healthier behaviours that may track into adulthood (Hayes 2019).
Why it is important to do this review
This systematic review was first published in 2009, with an update provided in 2013. Although the benefits of physical activity for healthy children have been documented, at the time the original review was conducted no other reviews had systematically examined the effectiveness of various combinations of school‐based interventions in promoting physical activity and fitness among children. Since that time, several new trials have been published (and are included in this update) and methodological advances have been made (e.g. using accelerometers rather than relying on self‐report data). The purpose of this update is to synthesise new data on the effectiveness of school‐based physical activity interventions with data included in the original review. This update includes evaluations of published studies indexed up to and including 1 June 2020.
Given that school‐aged children spend a significant amount of time in the school setting, and that many barriers prevent participation in physical activity outside of the school setting (e.g. resources, availability, cost), it is particularly important to understand the extent to which school‐based physical activity promotion interventions are effective in increasing activity and improving fitness levels. It is important to evaluate how these types of interventions may impact (positively or negatively) students' overall well‐being and health‐related quality of life and to discern any potential adverse events or harms. When school‐based interventions are combined with broader community‐based interventions, it is difficult to ascertain the impact of school‐based strategies. However, in developing comprehensive physical activity or chronic disease prevention strategies, it is crucial to incorporate effective school‐based strategies. Therefore, it is timely, given low worldwide participation in regular physical activity, that a review focused solely on the effectiveness of school‐based physical activity interventions be conducted and regularly updated.
Objectives
The purpose of this review update is to summarise the evidence on effectiveness of school‐based interventions in increasing moderate to vigorous physical activity and improving fitness among children and adolescents 6 to 18 years of age.
Specific objectives are:
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to evaluate the effects of school‐based interventions on increasing physical activity and improving fitness among children and adolescents;
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to evaluate the effects of school‐based interventions on improving body composition; and
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to determine whether certain combinations or components (or both) of school‐based interventions are more effective than others in promoting physical activity and fitness in this target population.
Methods
Criteria for considering studies for this review
Types of studies
In accordance with the last update, we included randomised controlled trials (RCTs) or cluster‐RCTs with a minimum intervention duration of 12 weeks. There are four unique departures from the protocol of this update in comparison to the original review.
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Due to growing availability and use of technology‐based assessments of physical activity and sedentary time via accelerometers, and known limitations of self‐report physical activity data for children in particular, we limited this review to studies that included a device‐based measure of physical activity or sedentary time (e.g. with accelerometers). This resulted in exclusion of measures related to TV watching time from the review, replaced by overall measures of sedentary time. This change in inclusion criteria resulted in exclusion from this update of several studies that included only self‐report measures that were included in the original review.
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Studies not primarily aimed at increasing levels of physical activity were excluded from this update. This resulted in exclusion of some studies that were primarily focused on nutrition or reducing/preventing obesity.
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Outcomes of blood pressure and pulse rate were excluded from this update. Again, this resulted in exclusion of a very small number of studies that included only these outcomes.
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For included studies, we extracted outcomes related to health‐related quality of life and adverse events when reported. This did not result in any change to inclusion or exclusion criteria.
The review authors are aware that post hoc questions are susceptible to bias (Higgins 2011); however, in light of the growing body of literature on the effectiveness of school‐based physical activity promotion interventions, we believe the changes in inclusion and exclusion criteria were necessary to ensure inclusion in this update of the most rigorous evidence related to the research question.
Types of participants
Studies that included school‐attending children and adolescents between the ages of 6 and 18 years were included in this review. This included all otherwise healthy children and adolescents, whether they were overweight or obese, or were not. We excluded studies in which participants received a physical activity intervention as part of a treatment regimen for a specific critical illness or comorbidity (e.g. diabetes). Study participants were categorised as children (age 6 to < 12) or adolescents (age 12 to 18) based on Centers for Disease Control and Prevention categories (Centers for Disease Control and Prevention, 2021).
Types of interventions
Interventions
We included any school‐based physical activity programme that aimed to increase physical activity and/or fitness among children and adolescents. We defined school‐based physical activity programmes as any that implemented educational, health promotion, counselling, and/or management strategies focused on promotion of physical activity and/or fitness. The range of interventions included changes to school curriculum, training for teachers about incorporating physical activity into school curriculum and routines, and educational materials for teachers, students, and parents. In some instances, the intervention included strategies to engage parents in the intervention, as well as community‐based strategies, mass media, policy development, and environmental changes. We included studies for which interventions were targeted primarily within the school setting. In some instances, interventions were implemented in the community and in the home, in addition to school‐based interventions, although the primary focus needed to be the school setting. Included studies must have fallen within public health practice (meaning the focus was on health promotion from an individual or population‐wide perspective and was not physician or clinic based) and must have been able to be implemented, facilitated, or promoted by staff in local public health units or by public health professionals.
Comparators
The comparison could be no intervention, usual care, or a concomitant intervention. Concomitant interventions had to be the same in both intervention and comparator groups to establish fair comparisons.
Minimum duration of intervention
The minimum duration of follow‐up was 12 weeks. Given the abundance of literature, this criterion was added during the last update to focus on interventions that were most likely to result in meaningful and sustainable changes in the school setting (Dobbins 2013). We extracted data on extended follow‐up periods. We defined extended follow‐up periods as follow‐up of participants that occurred once the original trial, as specified in the trial protocol, had been terminated (Buch 2011; Megan 2012).
Summary of specific exclusion criteria
We excluded studies in which participants received a physical activity intervention as part of a treatment regimen for a specific critical illness or comorbidity (e.g. diabetes), studies in which the intervention was conducted entirely outside the school setting (e.g. community setting, public place, recreation facility, physician office, camp setting), and studies in which the intervention could be delivered only by a specific health professional (e.g. physician) or fitness expert.
Types of outcome measures
To be included, studies had to report one or more of the following outcomes, presented as post‐intervention measurement and standard deviation or confidence intervals, or as change from baseline with standard deviation or confidence intervals.
Primary outcomes
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Proportion of students meeting recommendations for moderate to vigorous physical activity (MVPA)
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Duration of MVPA
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Sedentary time
Secondary outcomes
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Physical fitness
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Body mass index (BMI)
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Health‐related quality of life
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Adverse events
Method and timing of outcome measurement
Outcomes were primarily measured at baseline and immediately post intervention. In a small subset of studies, outcomes were measured at 6 months, at 9 months, and at 12 months, and in one study, up to 4 years post intervention.
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MVPA: assessed by accelerometers during school time or non‐school (or both) time. The proportion of students who met physical activity guidelines was presented as reported or calculated by dividing the number of students engaged in 60 minutes/d of MVPA by the total number of students allocated to either the intervention group or the control group; duration of physical activity was measured as total minutes per day or weeks spent engaged in MVPA.
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Sedentary time: measured as time spent sedentary in total minutes or hours per day or per week, measured via accelerometers.
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BMI (kg/m²or BMI z‐score): measured by trained health professionals using calibrated scales; however, differences existed across studies in terms of which clothes were worn by participants during measurement and whether height and weight were measured during school time.
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Physical fitness: measured in different ways by trained professionals. In some instances, actual maximal oxygen uptake (VO₂max) was measured; in many, a field‐based test such as a shuttle run or a step test was used to estimate VO₂max.
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Health‐related quality of life: quantified with a validated instrument (e.g. Pediatric Quality of Life Inventory). Assessments completed by both students and parent proxies were eligible.
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Adverse events: any as reported by study authors were noted, as were specific statements of no adverse events occurring.
Search methods for identification of studies
Electronic searches
The search for this update was conducted from the date of our last search (October 2011) to 1 June 2020. Some minor changes were made to the search strategy, such as using validated search filters for RCTs that were not available at the time of our last search and adding terms for sedentary time. Validated search filters were used within MEDLINE Ovid (Lefebvre 2019), Embase Ovid (Glanville 2019a), and Cumulative Index to Nursing and Allied Health Literature (CINAHL) (Glanville 2019b). We searched the following databases.
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Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library.
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MEDLINE Ovid.
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Embase Ovid.
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CINAHL EBSCO.
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PsycINFO Ovid.
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BIOSIS Web of Science.
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SPORTDiscus EBSCO.
-
Sociological Abstracts ProQuest.
For detailed search strategies, see Appendix 1. We placed no restrictions on language of publication when searching electronic databases or reviewing reference lists of identified trials.
Searching other resources
We tried to identify other potentially eligible trials or ancillary publications, including trial registries, by handsearching the reference lists of all included trials and relevant systematic reviews and meta‐analyses and health technology assessment reports that were identified in our search. We contacted authors of included trials to request additional information on retrieved trials and to determine if further trials exist, which we may have missed.
We did not use abstracts or conference proceedings for data extraction because this information source does not fulfil the Consolidated Standards of Reporting Trials (CONSORT) requirements, which call for "an evidence‐based, minimum set of recommendations for reporting randomised trials" (CONSORT 2018 Scherer 2007). However, we specified trial details in the Characteristics of studies awaiting classification table, and we contacted study authors to determine whether further publications exist.
Data collection and analysis
Selection of studies
For this update, two review authors (SNS, HC) independently screened abstract, title, or both, for every record retrieved in the literature searches, to determine which trials should be assessed further. We obtained the full text of all potentially relevant records. We resolved disagreements through consensus or by recourse to a third review author (MD). If we could not resolve a disagreement, we categorised the trial as a 'study awaiting classification' and contacted trial authors for clarification. We prepared an adapted PRISMA flow diagram to show the process of trial selection (Figure 1) (Liberati 2009). We listed all articles excluded after full‐text assessment in the Characteristics of excluded studies table and provided reasons for exclusion.
Trial flow diagram.
Data extraction and management
For trials that fulfilled our inclusion criteria, two review authors (SNS, HC) independently extracted key participant and intervention characteristics. We reported data on efficacy outcomes and adverse events using standardised data extraction sheets. We resolved disagreements by discussion, or, if required, we consulted a third review author (MD) (for details, see Characteristics of included studies; Table 1; Appendix 2; Appendix 3). We provided information including trial identifiers for potentially relevant ongoing trials in the Characteristics of ongoing studies table.
| Trial ID (design) | Interventions and comparators | Screened/eligible | Randomised | Finishing trial | Randomised finishing trial |
|---|---|---|---|---|---|
| I: Daily Mile | —/— | 1153 | 1107 | 96.0 | |
| C: usual school routine | 1127 | 1070 | 94.9 | ||
| total: | 2280 | 2177 | 95.5 | ||
| I: high‐intensity interval training during PE | —/— | — | 22 | — | |
| C: usual PE | 24 | ||||
| total: | — | 46 | |||
| — | |||||
| Belton 2019 (cluster‐RCT) | I: multi‐component PE, whole‐school and parent‐targeted intervention | 564/534 | 275 | 123 | 44.7 |
| C: usual care | 259 | 126 | 48.6 | ||
| total: | 534 | 249 | 46.6 | ||
| Corepal 2019 | I: pedometer challenge | —/— | 142 | 136 | 95.8 |
| C: usual school | 82 | 81 | 98.8 | ||
| total: | 224 | 217 | 96.9 | ||
| Ickovics 2019 (cluster‐RCT) | I1: PA school wellness policy | —/756 | 413 | 330 | 79.9 |
| I2: PA + nutrition school wellness policy | |||||
| C1: nutrition school wellness policy | 305 | 265 | 86.9 | ||
| C2: delayed control | |||||
| total: | 718 | 595 | 82.9 | ||
| Jago 2019 (cluster‐RCT) | I: Action 3:30R after‐school PA club | 1139/1125 | 170 | 113 | 66.5 |
| C: — | 165 | 139 | 84.2 | ||
| total: | 335 | 252 | 75.2 | ||
| Leahy 2019 (cluster‐RCT) | I: Burn2Learn, multi‐component high‐intensity interval training | —/68 | 38 | 32 | 84.2 |
| C: usual school activities | 30 | 29 | 96.7 | ||
| total: | 68 | 61 | 89.7 | ||
| Lonsdale 2019a | I: teacher PE training | —/1806 | 693 | 630 | 90.9 |
| C: standard teaching | 728 | 628 | 86.3 | ||
| total: | 1421 | 1258 | 88.5 | ||
| Müller 2019 | I1: PA only | 1009/944 | — | 265 | — |
| I2: PA + health education | |||||
| I3: PA + health education + nutrition | |||||
| C1: health education + nutrition | — | 398 | — | ||
| C2: no PA | |||||
| total: | 944 | 663 | 70.2 | ||
| I: 2 x 45‐minute PE sessions per week and daily run | —/— | — | 45 | — | |
| C: 2 x 45‐minute PE sessions per week | — | 44 | — | ||
| total: | — | 89 | — | ||
| I: 4 core strategies to increase PA | —/— | 2495 | — | — | |
| C: usual PE | 2399 | — | — | ||
| total: | 4894 | — | — | ||
| Seljebotn 2019 | I: physically active lessons, active homework, physically active recess | —/473 | 228 | 224 | 98.2 |
| C: continued normal routine, approximately 135 minutes/week of PA | 219 | 218 | 99.5 | ||
| total: | 447 | 442 | 98.9 | ||
| Zhou 2019 | I1: modified PE | —/— | 204 | 163 | 79.9 |
| I2: after school PA programme | 200 | 180 | 90.0 | ||
| I3: modified PE and after school PA programme | 178 | 168 | 94.4 | ||
| C: regular PE | 176 | 170 | 96.6 | ||
| total: | 758 | 681 | 89.8 | ||
| Adab 2018 | I: 30 minutes of additional MVPA on each school day, cooking workshops, a 6‐week healthy eating programme, information sheets for families | —/— | 1134 | 660 | 58.2 |
| C: ongoing Year 2 health‐related activities and education resources, excluding topics related to healthy eating and PA | 1328 | 732 | 55.1 | ||
|
| total: | 2462 | 1392 | 56.5 | |
| Carlin 2018 | I: brisk walking intervention | —/— | 101 | 100 | 99.0 |
| C: continued with normal PA habits | 98 | 97 | 99.0 | ||
| total: | 199 | 197 | 99.0 | ||
| Harrington 2018 | I: support for PA, PE, and school sport culture and practices with support of the Youth Sport Trust and a hub school | —/1753 | 867 | 735 | 84.8 |
| C: usual practice of PE and sport | 885 | 626 | 70.7 | ||
| total: | 1752 | 1361 | 77.7 | ||
| Have 2018 | I: active math lessons | —/557 | 294 | 268 | 91.2 |
| C: regular classroom instruction | 211 | 182 | 86.3 | ||
| total: | 505 | 450 | 89.1 | ||
| Pablos 2018 | I: lunchtime extracurricular PA | —/210 | 100 | 82 | 82.0 |
| C: continued with daily activities | 90 | 76 | 84.4 | ||
| total: | 190 | 158 | 83.2 | ||
| Robbins 2018 | I: an after school PA club, counselling, interactive Internet‐based sessions | 4192/1543 | 766 | 706 | 92.2 |
| C: no additional after school programming | 777 | 680 | 87.5 | ||
| total: | 1543 | 1386 | 89.8 | ||
| Siegrist 2018 | I: weekly lifestyle lessons | 792/— | 331 | 243 | 73.4 |
| C: usual activities | 257 | 191 | 74.3 | ||
| total: | 588 | 434 | 73.8 | ||
| Ten Hoor 2018 | I: strength training and motivational interviewing | —/808 | 353 | 262 | 74.2 |
| C: usual curriculum | 342 | 246 | 71.9 | ||
| total: | 695 | 508 | 73.1 | ||
| Donnelly 2017 | I: Academic Achievement and Physical Activity Across the Curriculum lessons, 160 minutes/week of MVPA | —/698 | 316 | 244 | 77.2 |
| C: traditional classroom instruction and typical PE schedule | 268 | 204 | 76.1 | ||
| total: | 584 | 448 | 76.7 | ||
| Farmer 2017 | I: school‐specific playground action plan | —/— | 812 | 344 | 42.4 |
| C: no change to school play spaces | 851 | 325 | 38.2 | ||
| total: | 1663 | 669 | 40.2 | ||
| Sutherland 2017 | I: modified Supporting Children's Outcomes using Rewards, Exercise and Skills programme | —/1959 | 571 | — | — |
| C: delivered school PA practices according to the curriculum | 568 | — | — | ||
| total: | 1139 | — | — | ||
| Torbeyns 2017 (RCT) | I: cycling desks | —/— | 28 | 21 | 75.0 |
| C: no lifestyle change | 28 | 23 | 82.1 | ||
| total: | 56 | 44 | 78.6 | ||
| Daly 2016 | I: specialist‐taught PE intervention | —/— | 457 | 273 | 59.7 |
| C: usual PE programme | 396 | 267 | 67.4 | ||
| total: | 853 | 540 | 63.3 | ||
| de Greeff 2016 | I: physically active mathematics and language lessons | —/— | — | 181 | — |
| C: usual curriculum | — | 195 | — | ||
| total: | 388 | 376 | 96.9 | ||
| Drummy 2016 | I: teacher‐led activity break | —/150 | — | 54 | — |
| C: normal daily routine | — | 53 | — | ||
| total: | 120 | 107 | 89.2 | ||
| Jarani 2016 | I1: group circuit training‐based PE | —/767 | 261 | 253 | 96.9 |
| I2: games‐based PE | 251 | 243 | 96.8 | ||
| C: traditional PE school | 255 | 240 | 94.1 | ||
| total: | 767 | 736 | 96.0 | ||
| Kocken 2016 | I: theory and practical lessons on nutrition and PA | —/— | 615 | 367 | 59.7 |
| C: regular school programme or curriculum on nutrition and PA | 497 | 496 | 99.8 | ||
| total: | 1112 | 863 | 77.6 | ||
| Lau 2016 (RCT) | I: Xbox 260 Kinect gaming sessions after school | 152/84 | 40 | 40 | 100.0 |
| C: regular PA and PE class | 40 | 40 | 100.0 | ||
| total: | 80 | 80 | 100.0 | ||
| Resaland 2016 | I: physically active Norwegian, mathematics, and English lessons on the playground; PA breaks and PA homework | 1395/1202 | 620 | 593 | 95.6 |
| C: curriculum‐prescribed PE and PA | 582 | 530 | 91.1 | ||
| total: | 1202 | 1123 | 93.4 | ||
| Sutherland 2016 | I: 7 PA intervention strategies and 6 implementation strategies | —/1468 | 696 | 250 | 35.9 |
| C: only measurement components of the trial: regular PA and PE | 537 | 191 | 35.6 | ||
| total: | 1233 | 441 | 35.8 | ||
| Tarp 2016 | I: 60 minutes of PA during schooltime, PA homework | 869/855 | 215 | 194 | 90.2 |
| C: normal practice | 490 | 438 | 89.4 | ||
| total: | 705 | 632 | 89.6 | ||
| Cohen 2015 | I: teacher learning, PA policies, school‐community linkages | —/— | 199 | 166 | 83.4 |
| C: usual PE and school sport programmes | 261 | 217 | 83.1 | ||
| total: | 460 | 383 | 83.3 | ||
| Jago 2015 | I: after school dance classes | —/663 | 284 | — | — |
| C: provided data only | 287 | — | — | ||
| total: | 571 | 508 | 89.0 | ||
| Madsen 2015 | I: nutrition education curriculum, Playworks structured recess before or after school activities, PA and games implemented by teachers | —/— | 583 | 446 | 76.5 |
| C: — | 296 | 230 | 77.7 | ||
| total: | 879 | 676 | 76.9 | ||
| Muros 2015 | I1: extracurricular PA sessions | 242/162 | 28 | 28 | 100.0 |
| I2: PA and nutrition | 21 | 21 | 100.0 | ||
| I3: PA and nutrition and extra virgin olive oil during the final month | 25 | 25 | 100.0 | ||
| C1: nutrition and lifestyle education sessions | 41 | 41 | 100.0 | ||
| C2: usual activities | |||||
| total: | 135 | 135 | 100.0 | ||
| Suchert 2015 | I: multi‐level intervention targeting students, classrooms, schools, and parents | —/1489 | 790 | 702 | 88.9 |
| C: no intervention | 506 | 460 | 90.9 | ||
| total: | 1296 | 1162 | 89.7 | ||
| Andrade 2014 | I: ACTIVITAL individual‐ and environment‐based intervention | —/— | 700 | 550 | 78.6 |
| C: standard curriculum | 740 | 533 | 72.0 | ||
| total: | 1440 | 1083 | 75.2 | ||
| Jago 2014 | I: Action 3:30 activity club | —/— | 284 | 153 | 53.9 |
| C: schools provided data only | 255 | 157 | 61.6 | ||
| total: | 539 | 310 | 57.5 | ||
| Kipping 2014 | I: PA education intervention | 2242/2221 | 1064 | — | — |
| C: continued standard education provision | 1157 | — | — | ||
| total: | 2221 | 1252 | 56.4 | ||
| Kobel 2014 | I: teacher training, PA education, active breaks | 3159/1968 | — | — | — |
| C: no intervention | — | — | — | ||
| total: | 1964 | 1724 | 87.8 | ||
| Martinez‐Vizcaino 2014 (cluster‐RCT) | I: MOVI‐2 extracurricular PA programme | —/— | 769 | 420 | 54.6 |
| C: standard PE curriculum | 823 | 492 | 59.8 | ||
| total: | 1592 | 912 | 57.3 | ||
| Nogueira 2014 | I: high‐intensity capoeira sessions | 341/339 | 185 | 176 | 95.1 |
| C: usual school activities | 154 | 135 | 87.7 | ||
| total: | 339 | 138 | 40.7 | ||
| Santos 2014 | I: healthy buddies, healthy living lessons, structured aerobic exercise | —/— | 340 | 310 | 91.2 |
| C: standard curriculum | 347 | 273 | 78.7 | ||
| total: | 687 | 583 | 84.9 | ||
| Toftager 2014 | I: physical and organisational environmental changes | —/— | 623 | 551 | 88.4 |
| C: — | 725 | 608 | 83.9 | ||
| total: | 1348 | 1159 | 86.0 | ||
| Fairclough 2013 | I: weekly lesson plans, worksheets, homework tasks, lesson resources | 420/318 | 166 | 117 | 70.5 |
| C: normal instruction | 152 | 89 | 58.6 | ||
| total: | 318 | 196 | 61.6 | ||
| Ford 2013 (RCT) | I: accumulated brisk walking programme | —/174 | — | 77 | — |
| C: normal school lessons | — | 75 | — | ||
| total: | 174 | 152 | 87.4 | ||
| Grydeland 2013 | I: structured lessons, PA breaks, PA promotion | —/— | 784 | 519 | 66.2 |
| C: — | 1381 | 945 | 68.4 | ||
| total: | 2165 | 1464 | 67.6 | ||
| Melnyk 2013 | I: goal‐setting, education, PA homework | 1560/807 | 374 | 286 | 76.5 |
| C: Healthy Teens attention control curriculum was intended to promote knowledge of common adolescent health topics and health literacy | 433 | 341 | 78.8 | ||
| total: | 807 | 627 | 77.7 | ||
| Sacchetti 2013 | I: daily PA in schoolyard and classroom | 521/521 | 247 | 212 | 85.8 |
| C: standard programme of PE | 250 | 216 | 86.4 | ||
| total: | 497 | 428 | 86.1 | ||
| Siegrist 2013 | I: JuvenTUM educational and environmental intervention | —/902 | 486 | 427 | 87.9 |
| C: continued with usual school activities | 340 | 297 | 87.4 | ||
| total: | 826 | 724 | 87.7 | ||
| Aburto 2011 | I1: basic intervention of environmental and policy‐level changes | —/— | 262 | 241 | 92.0 |
| I2: plus intervention adding additional resources and daily morning exercise | 264 | 242 | 91.7 | ||
| C: no change to standard practices | 338 | 216 | 63.9 | ||
| total: | 864 | 699 | 80.9 | ||
| Ardoy 2011 | I1: 4 sessions/week of PE | 70/67 | 26 | 25 | 96.2 |
| I2: 4 sessions/week of PE with emphasis on increasing intensity | 23 | 23 | 100.0 | ||
| C: 2 sessions/week of PE | 18 | 18 | 100.0 | ||
| total: | 67 | 66 | 98.5 | ||
| de Heer 2011 | I: Bienstar intervention of health education and 45 to 60 minutes of after school PA | 1720/901 | 292 | 242 | 82.9 |
| C1: Grade 4 health workbooks and incentives | 251 | 236 | 94.0 | ||
| C2: spillover control group | 354 | 326 | 92.1 | ||
| total: | 897 | 804 | 89.6 | ||
| Jago 2011 | I: education, social marketing, food environment, PE curriculum, equipment provision | —/11158 | 5571 | 2060 | 37.0 |
| C: recruitment and data collection only | 5587 | 2003 | 35.9 | ||
| total: | 11158 | 4063 | 36.4 | ||
| Jansen 2011 | I: 3 PE sessions/week, additional after school sport and play, classroom education, parent health promotion | —/— | 1271 | 1149 | 90.4 |
| C: continued with usual curriculum | 1499 | 1267 | 84.5 | ||
| total: | 2770 | 2416 | 87.2 | ||
| Magnusson 2011 | I: students engaged in PA during PE lessons, during recess, and during classes; schools had access to PA equipment to use in school lessons; teaching materials promoting PA were provided | —/321 | 151 | 138 | 91.4 |
| C: followed the general PA curriculum | 170 | 116 | 68.2 | ||
| total: | 321 | 254 | 79.1 | ||
| Okely 2011 | I: PA action plan | —/1769 | 771 | 566 | 73.4 |
| C: continuation of usual programmes | 747 | 633 | 84.7 | ||
| total: | 1518 | 1199 | 79.0 | ||
| Thivel 2011 | I: 120 minutes of additional supervised PE | —/— | 229 | 229 | 100.0 |
| C: habitual 2 hours of PE/week | 228 | 228 | 100.0 | ||
| total: | 457 | 457 | 100.0 | ||
| Wilson 2011 | I: Active by Choice Today programme, PA homework, in‐school PA, motivational skills training | 729 | 673 | 92.3 | |
| C: General Health Education Programme | 693 | 635 | 91.6 | ||
| total: | 1422 | 1308 | 92.0 | ||
| Kriemler 2010 | I: 2 additional 45‐minute PE lessons/week, activity breaks, PA homework | 305 | 297 | 97.4 | |
| C: usual mandatory PE lessons | 235 | 205 | 87.2 | ||
| total: | 540 | 502 | 93.0 | ||
| Neumark‐Sztainer 2010 | I: New Moves curriculum (nutrition and self‐empowerment, motivational interviewing, lunch meetings, parent outreach) | 687 | 182 | 177 | 97.3 |
| C: participation in all‐girls PE class | 174 | 159 | 91.4 | ||
| total: | 356 | 336 | 94.4 | ||
| Angelopoulos 2009 | I: educational intervention covering self‐esteem, body image, nutrition, PA, fitness, and environmental issues, with motivational methods to increase knowledge, skills, self‐efficacy, self‐monitoring, and social influence | — | 321 | — | |
| C: — | — | 325 | — | ||
| total: | — | 646 | — | ||
| Donnelly 2009 | I: 90 minutes/week of moderate to | 814 | 792 | 97.3 | |
| C: regular classroom instruction | 713 | 698 | 97.9 | ||
| total: | 1527 | 1490 | 97.6 | ||
| Dorgo 2009 | I1: PE manual resistance training programme | 141 | 93 | 66.0 | |
| I2: PE manual resistance training plus | |||||
| C: regular PE programme that followed | 232 | 129 | 55.6 | ||
| total: | 373 | 222 | 59.5 | ||
| Gentile 2009 | I: 'Switch' programme: promoted | 670 | — | — | |
| C: no intentional exposure to the Switch programme | 653 | — | — | ||
| total: | 1323 | 1029 | 77.8 | ||
| Neumark‐Sztainer 2009 | I: after school theatre sessions, booster | 56 | 51 | 91.1 | |
| C: a theatre‐based control condition | 52 | 45 | 86.5 | ||
| total: | 108 | 96 | 88.9 | ||
| Peralta 2009 (RCT) | I: curriculum and peer‐facilitated | 16 | 16 | 100.0 | |
| C: PA curriculum | 17 | 16 | 94.1 | ||
| total: | 33 | 32 | 97.0 | ||
| Walther 2009 | I: 1 unit of physical exercise (45 minutes) | 112 | 109 | 97.3 | |
| C: German standards, 2 units (each 45 | 76 | 73 | 96.1 | ||
| total: | 188 | 182 | 96.8 | ||
| Reed 2008 | I: Action Schools!BC whole‐school PA | 178 | 156 | 87.6 | |
| C: regular programme of PE and | 90 | 81 | 90.0 | ||
| total: | 268 | 237 | 88.4 | ||
| Salmon 2008 | I: 1, 2, 3 behavioural modification group; fundamental motor skills group; combined behavioural modification and fundamental motor skills group | 233 | 213 | 91.4 | |
| C: usual classroom lessons | 62 | 55 | 88.7 | ||
| total: | 295 | 268 | 90.8 | ||
| Wang 2008 | I: 'FitKid' after school intervention sessions | 603 | 260 | 43.1 | |
| C: — | 584 | 265 | 45.4 | ||
| total: | 1187 | 525 | 44.2 | ||
| Webber 2008 | I: health education lessons to enhance | — | — | — | |
| C: — | — | — | — | ||
| total: | 3502 | 3378 | 96.5 | ||
| Weeks 2008 (RCT) | I: directed jumping activity at the beginning | 52 | 43 | 82.7 | |
| C: regular PE warm‐ups and stretching | 47 | 38 | 80.9 | ||
| total: | 99 | 81 | 81.8 | ||
| Barbeau 2007 (RCT) | I: after school PA programme | — | — | 81 | |
| C: — | — | — | 84 | ||
| total: | — | — | — | ||
| Williamson 2007 | I: Healthy Eating and Exercise programme | 313 | 282 | 90.1 | |
| C: Alcohol/Drug/Tobacco abuse prevention | 348 | 304 | 87.4 | ||
| total: | 661 | 586 | 88.7 | ||
| Haerens 2006 | I1: a computer‐tailored intervention | 2105 | — | — | |
| I2: group 1 plus parental involvement | |||||
| C: no PA and nutrition intervention | 735 | — | — | ||
| total: | 2840 | 2434 | 85.7 | ||
| Young 2006 (RCT) | I: PE curriculum taught 5 days/week | 116 | 111 | 95.7 | |
| C: standard PE class | 105 | 99 | 94.3 | ||
| total: | 221 | 210 | 95.0 | ||
| Bayne‐Smith 2004 (RCT) | I: Physical Activity and Teenage Health | — | 310 | — | |
| C: same frequency or duration of PE | — | 132 | — | ||
| total: | — | 442 | — | ||
| Simon 2004 | I: an educational component focusing | — | 475 | — | |
| C: — | — | 479 | — | ||
| total: | 1046 | 954 | 91.2 | ||
| Trevino 2004 | I: health programming regarding 3 | 969 | 619 | 63.9 | |
| C: — | 1024 | 602 | 58.8 | ||
| total: | 1993 | 1221 | 61.3 | ||
| Stone 2003 | I: food service, skills‐based classroom | 879 | 644 | 73.3 | |
| C: — | 825 | 653 | 79.2 | ||
| total: | 1704 | 1297 | 76.1 | ||
| Burke 1998 | I1: standard PA and nutrition programme | — | — | — | |
| I2: I1 plus a PA enrichment programme | |||||
| C: no programme | — | — | — | ||
| total: | 800 | 720 | 90.0 | ||
| Ewart 1998 (RCT) | I: 50‐minute 'Project Heart' aerobic exercise classes | 45 | 44 | 97.8 | |
| C: 50‐minute standard PE classes | 54 | 44 | 81.5 | ||
| total: | 99 | 88 | 88.9 | ||
| Luepker 1996 | I1: school food service modifications, | 3651 | 3297 | 90.3 | |
| I2: I1 plus a family‐based programme | |||||
| C: usual health curricula, PE, and food | 1455 | 722 | 49.6 | ||
| total: | 5106 | 4019 | 78.7 | ||
| Bush 1989 | I1: 'Know Your Body' curriculum focusing | — | — | — | |
| I2: 'Know Your Body' curriculum and | |||||
| C: health screening only | — | — | — | ||
| total: | 892 | 431 | 48.3 | ||
| Walter 1988 | I: special curriculum targeting voluntary | — / 3388 | 2075 | 1104 | 53.2 |
| C: — | 1313 | 665 | 50.6 | ||
| total: | 3388 | 1769 | 52.2 | ||
| Grand total | All interventions | 46 073 | 28 089 | ||
| All c omparators | 40 566 | 23 639 | |||
| All interventions and c omparators b | 96 740 | 66 752 | |||
—: denotes not reported.
aFollow‐up under randomised conditions until end of trial (= duration of intervention + follow‐up post intervention or identical to duration of intervention); extended follow‐up refers to follow‐up of participants once the original trial was terminated as specified in the power calculation.
bNote that numbers from all interventions and all interventions and comparators are greater than the sum of interventions only and comparators only, as some studies reported only the total number of included participants and did not note numbers within each group.
C: comparator; I: intervention; MVPA: moderate to vigorous physical activity; NA: not applicable; PA: physical activity; PE: physical education; RCT: randomised controlled trial.
We emailed all authors of included trials to enquire whether they would be willing to answer questions regarding their trials. We thereafter sought relevant missing information on the trial from the primary trial author(s), if required.
Dealing with duplicate and companion publications
In the event of duplicate publications, companion documents, or multiple reports of a primary trial, we maximised the information yield by collating all available data, and we used the most complete data set aggregated across all known publications. We listed duplicate publications, companion documents, multiple reports of a primary trial, and trial documents of included trials (such as trial registry information) as secondary references under the study identifier (ID) of the included trial. Furthermore, we listed duplicate publications, companion documents, multiple reports of a trial, and trial documents of excluded trials (such as trial registry information) as secondary references under the study ID of the excluded trial.
Assessment of risk of bias in included studies
For this review, all newly included studies were assessed independently for risk of bias by two review authors (SNS, HC) according to six domains (sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessors, incomplete outcome data, and selective reporting) using the ‘Risk of Bias 1’ tool in the Cochrane Handbook for Systematic Reviews of Interventions to assign assessment of low, high, or unclear risk of bias (for details, see Appendix 4) (Higgins 2017). Incomplete outcome data were rated separately for (1) device‐based measures of physical activity and sedentary time, and (2) BMI and fitness, due to the large proportion of missing data that is often seen in studies using accelerometers. For studies that used a cluster‐randomised design, four additional domains (recruitment bias, baseline imbalance, loss of clusters, and incorrect analysis) were assessed. All disagreements were resolved through discussion. If adequate information was unavailable, trial authors were contacted to request missing data on ‘Risk of bias’ items.
Two main changes were made to the assessment of risk of bias for this update. First, due to changes to Cochrane recommendations, blinding is now assessed separately for participants and personnel, and outcome assessors. Previously included studies were re‐assessed for this domain. In this update, we do not include assessment for control for confounders or reliability and validity of data collection methods. Second, previously included studies that utilised a cluster‐randomised design were appraised for the four new cluster‐randomised trial domains. Finally, assessment of 'other' risk of bias has been removed.
Risk of bias for an outcome across trials and across domains
These are the main summary assessments that we incorporated into our judgements about quality of evidence in summary of findings Table 1. We defined outcomes as at low risk of bias when most weight in the meta‐analysis comes from trials at low risk of bias, unclear risk when most weight in the meta‐analysis comes from trials at low or unclear risk of bias, and high risk when a sufficient proportion of information comes from trials at high risk of bias. We defined single studies as having low risk of bias when all but one domain was assessed to be at low risk of bias, or when all but two domains were assessed at low risk of bias, one of which was 'blinding of participants and personnel', as adequate blinding of study participants is nearly impossible to do well in school‐based physical activity interventions. We defined single studies to be at high risk of bias when at least three domains were assessed as having unclear or high risk of bias, or when four domains were assessed as having unclear or high risk of bias, one of which was 'blinding of participants and personnel'.
Measures of treatment effect
When at least five included trials were available for comparison of a given outcome measured on the same scale (e.g. MVPA in minutes/d), we combined effects into a meta‐analysis. When available, we extracted data on post‐intervention values adjusted for baseline differences, along with confidence intervals or standard deviation. When only changes from baseline were reported, these differences, along with confidence intervals or standard deviations, were extracted. Both were combined in meta‐analyses, with the calculator function in RevMan 5.4 used to calculate adjusted between‐group difference, as outlined in the Cochrane Handbook for Systematic Reviews of Interventions (Deeks 2021).
When possible, we combined multiple study groups into a single pairwise comparison using formulae for combining continuous data from multiple groups as provided in the Cochrane Handbook for Systematic Reviews of Interventions when separate data were presented for each group, or when between‐group comparisons from multiple group had independent control groups (e.g. when results were presented separately for boys and girls or by grade level) (Higgins 2017). When between‐group differences were reported between multiple intervention groups and the same control group, we did not include these data in the meta‐analysis, so as not to double‐count participants in control groups.
Unit of analysis issues
We considered the level at which randomisation occurred, such as cluster‐randomised trials and multiple observations for the same outcome. If more than one comparison from the same trial was eligible for inclusion in the same meta‐analysis, we used the end of intervention comparison.
Standard errors for cluster‐RCTs that were not appropriately adjusted for potential clustering of participants within clusters in analyses were adjusted using the design effect (1 + (M‐1) × ICC), where M is the average cluster size, and ICC is the intraclass correlation coefficient (Higgins 2017). The ICC was estimated at 0.01, as has been previously reported (Murray 2006).
Dealing with missing data
If possible, we obtained missing data from authors of included trials. We carefully evaluated important numerical data such as screened, randomly assigned participants, as well as intention‐to‐treat and as‐treated and per‐protocol populations. We investigated attrition rates (e.g. dropouts, losses to follow‐up, withdrawals), and we critically appraised issues concerning missing data and use of imputation methods (e.g. last observation carried forward). When included trials did not report sufficient data for inclusion in the meta‐analysis (e.g. provided only P values) and we did not receive requested information from trial authors, we did not include these studies in the meta‐analysis; however, we included them in the narrative tables.
Assessment of heterogeneity
We identified heterogeneity (inconsistency) by visually inspecting forest plots and by using a standard Chi² test with a significance level of α = 0.1 (Deeks 2021). In view of the low power of this test, we also considered the I² statistic, which quantifies inconsistency across trials to assess the impact of heterogeneity on the meta‐analysis (Higgins 2002; Higgins 2003). When we found heterogeneity, we attempted to determine possible reasons for this by examining individual trial and subgroup characteristics in the narrative summary.
Assessment of reporting biases
If we included 10 or more trials that investigated a particular outcome, we planned to use funnel plots to assess small‐trial effects. Several explanations may account for funnel plot asymmetry, including true heterogeneity of effect with respect to trial size, poor methodological design (and hence bias of small trials), and publication bias (Sterne 2017).
Data synthesis
We planned to undertake (or display) a meta‐analysis only if we judged participants, interventions, comparisons, and outcomes to be sufficiently similar to ensure an answer that is clinically meaningful. We used random‐effects meta‐analyses to calculate the mean of the effects of included studies (Borenstein 2017a; Borenstein 2017b; Higgins 2009). We performed statistical analyses according to the statistical guidelines presented in the Cochrane Handbook for Systematic Reviews of Interventions (Deeks 2021).
When studies could not be included in the meta‐analysis, for example, because they did not report the required data or they measured the outcome in a format that was incompatible with other studies, we summarised results from each study under Results and in table form. We used vote counting based on the direction of effect to determine whether the majority of studies found a positive or negative effect (McKenzie 2021).
Subgroup analysis and investigation of heterogeneity
Given the differences between children and adolescents with respect to school setting, types of interventions, etc., we explored the effects of interventions on these two age groups separately, using the subgroup function in Review Manager 5.4.
Given the substantial heterogeneity in types of interventions included, we conducted secondary analyses to synthesise results with respect to each outcome type by subcategories of intervention types. For this purpose, we broadly categorised each intervention type as primarily focused on (1) before or after school physical activity programmes, for example, after school dance clubs, walk to school programmes; (2) enhanced PE classes that focused on increasing the frequency, duration, intensity, or types of activities above and beyond the usual PE classes; (3) multi‐component interventions that typically included a whole‐school approach and utilised multiple strategies including environmental changes to increase physical activity, and often promoted healthy eating or healthy weight amongst students; and (4) schooltime physical activity interventions, such as active academic lessons or cycling desk interventions that focused on integrating physical activity throughout the school day itself rather than restricting physical activity to recess or PE classes.
Sensitivity analysis
We performed no sensitivity analyses.
Summary of findings and assessment of the certainty of the evidence
We used the GRADE approach to assess overall certainty of evidence for each of the primary and secondary outcome measures. GRADE takes into account issues related to both internal and external validity to state how confident we are in the effect estimates presented. Two review authors (SNS, HC) independently rated the certainty of evidence for each outcome. We resolved differences in assessment by discussion. For each outcome, we rated evidence certainty as very low, low, moderate, or high based on the GRADE domains as described in Chapter 14 of the Cochrane Handbook for Systematic Reviews of Interventions (Schünemann 2021). As only RCTs were included, the starting point for certainty of evidence was high. Then we considered each GRADE domain to determine whether downgrading of certainty was needed based on:
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risk of bias ‐ based on critical appraisal using the Cochrane 'Risk of bias' tool;
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inconsistency of results ‐ based on visual inspection of forest plots and I² in meta‐analyses and consistency of effects reported across narrative syntheses;
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indirectness ‐ based on the validity of outcome measures used and how directly they measured the outcome of interest, for example, studies that measure VO₂ peak as a direct measure of fitness provide greater certainty than studies that report estimated fitness based on functional tests;
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publication bias ‐ based on a small number of studies or indication of publication bias based on funnel plots; and
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imprecision ‐ based on width of the confidence intervals, and whether they include the possibility of a small or null effect.
We presented a summary of the evidence in summary of findings Table 1. This provides key information about the best estimate of the magnitude of effect as absolute differences for each relevant comparison, numbers of participants and trials addressing each important outcome, and a rating of overall confidence in effect estimates for each outcome. We created the 'Summary of findings' table using the methods described in the Cochrane Handbook for Systematic Reviews of Interventions (Schünemann 2021), along with Review Manager (RevMan 5.4) table editor (RevMan 2014). We reported the following outcomes, listed according to priority.
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MVPA (proportion meeting guidelines, duration).
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Sedentary time.
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Physical fitness.
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BMI.
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Health‐related quality of life.
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Adverse events.
Results
Description of studies
For a detailed description of trials, see Table 1, Characteristics of included studies, Characteristics of excluded studies, and Characteristics of ongoing studies sections.
Results of the search
A total of 16,219 records related to physical activity interventions with children and adolescents were identified for the last update. Of these, 587 studies were assessed for eligibility, and 44 were deemed to meet the criteria for inclusion in the review. The most common reasons studies were judged as not relevant were data on relevant outcomes not reported, studies not RCTs, and studies not relevant to public health.
For this update, when the new inclusion and exclusion criteria were applied (i.e. only studies in which the primary aim was to increase levels of physical activity and that included an objective measure of physical activity, physical fitness, or body composition), 16 of the original 44 studies were excluded: 11 included only self‐report measures (Araujo‐Soares 2009a; Colin‐Ramirez 2010; Dishman 2004; Haerens 2006; Jones 2008; Kipping 2008; Lubans 2009; McManus 2008; Petchers 1988; Singhal 2010; Verstraete 2006); three did not include any measure of physical activity or physical fitness (Li 2010; Martinez 2008; Stephens 1998); and two did not have a primary objective to increase physical activity (Robinson 1999; Singh 2009). Therefore, this update includes 28 of the 44 studies included in the last update (Angelopoulos 2009; Barbeau 2007; Bayne‐Smith 2004; Burke 1998; Bush 1989; Donnelly 2009; Dorgo 2009; Ewart 1998; Gentile 2009; Haerens 2006; Kriemler 2010; Luepker 1996; Neumark‐Sztainer 2009; Neumark‐Sztainer 2010; Peralta 2009; Reed 2008; Salmon 2008; Simon 2004; Stone 2003; Trevino 2004; Walter 1988; Walther 2009; Wang 2008; Webber 2008; Weeks 2008; Williamson 2007; Wilson 2011; Young 2006).
The search strategy for this update from October 2011 to June 2020 yielded 9968 records. Of these, 978 unique full texts were assessed for eligibility. A total of 61 studies met all relevance criteria and were included in this update (Aburto 2011; Adab 2018; Andrade 2014; Ardoy 2011; Belton 2019; Breheny 2020; Carlin 2018; Cohen 2015; Corepal 2019; Daly 2016; de Greeff 2016; de Heer 2011; Donnelly 2017; Drummy 2016; Fairclough 2013; Farmer 2017; Ford 2013; Grydeland 2013; Harrington 2018; Have 2018; Ickovics 2019; Jago 2011; Jago 2014; Jago 2015; Jago 2019; Jansen 2011; Jarani 2016; Ketelhut 2020; Kipping 2014; Kobel 2014; Kocken 2016; Lau 2016; Leahy 2019; Lonsdale 2019a; Madsen 2015; Magnusson 2011; Martinez‐Vizcaino 2014; Melnyk 2013; Müller 2019; Muros 2015; Nogueira 2014; Okely 2011; Ordóñez Dios 2019; Pablos 2018; Resaland 2016; Robbins 2018; Sacchetti 2013; Santos 2014; Seibert 2019; Seljebotn 2019; Siegrist 2013; Siegrist 2018; Suchert 2015; Sutherland 2016; Sutherland 2017; Tarp 2016; Ten Hoor 2018; Thivel 2011; Toftager 2014; Torbeyns 2017; Zhou 2019). The most common reasons studies were judged as not relevant were (1) studies were not RCTs; (2) no device‐based measure of physical activity or physical fitness was included; and (3) the intervention lasted < 12 weeks. This update includes 89 studies (28 from the last review and 61 from this update). A flow diagram depicting these results is presented in Figure 1.
A total of 84 authors were contacted for missing information, and 126 responses were received (median 1 response, range 0 to 4). In most cases, study authors were able to provide clarification on risk of bias or study characteristics, but few of them provided updated outcome data.
Included studies
In addition to information included in the Characteristics of included studies table, we have presented greater detail for each study in Table 1 (overview of study populations) and in Appendix 2 (baseline characteristics). The following is a succinct overview.
Trial design
All included studies were RCTs, with nine randomising participants at the level of the individual, and 80 using a cluster design, whereby schools or classrooms were the unit of randomisation. Across comparator groups, a majority of comparator groups (n = 67) specified continuation of usual school curriculum, standard PE, or no intervention; others reported offering a delayed intervention (n = 3). Some comparator groups included an intervention unrelated to physical activity, such as nutrition education, theatre play group, or education about alcohol or tobacco use (n = 10), and 13 of the comparator groups were not clearly described. The number of included schools ranged from 1 to 96. Most trials were multi‐centre (n = 81), and only 8 trials were conducted within a single school. A total of 31 trials were conducted in 2 to 10 schools, 27 trials in 11 to 20 schools, and 23 trials in more than 20 schools. A majority of trials were not double‐blinded; only 9 of 89 trials reported blinding participants, personnel, and outcome assessors; 6 trials reported blinding participants and personnel but not outcome assessors; and 24 trials reported blinding outcome assessors but not participants or personnel; the remaining 50 trials did not report blinding at all. Trials were conducted from 1983 to 2018. Duration of intervention ranged from 12 weeks to 6 years. Trials were most commonly 12 weeks to 6 months in duration (n = 31), followed by longer than 6 months to 1 year (n = 29), 1 to 2 years (n = 17), and longer than 2 years (n = 12). A majority of studies evaluated only outcomes immediately following the intervention (n = 72); others collected additional data during post‐intervention follow‐up (n = 17). Post‐intervention follow‐up ranged from 2 weeks to 1 year. No trials described a run‐in period, and no trials reported that they were terminated before the planned end of study.
Participants
Across all studies, 96,740 participants were randomised, with at least 46,073 individuals in intervention groups and 40,566 in comparator groups, as not all studies reported the exact numbers randomised to each group. A total of 66,752 participants completed the trials and were included in the analyses. The number of participants randomised ranged from 33 to 11,158, and the number of participants completing trials ranged from 32 to 4063. The average percentage of participants completing the trials was 69.0%, ranging from 35.7% to 100%. Within intervention groups, the average percentage of participants completing the trial was 60.9%, and within control groups, 58.3%, when reported.
A majority of studies were conducted in children 12 years of age or younger at baseline (n = 56); others included only adolescents between the ages of 12 and 18 (n = 22), and some included both children and adolescents (n = 10). One study did not report the age of participants. Most included studies were conducted in the USA (n = 26), Australia (n = 12), and the UK (n = 9). Other countries included Germany (n = 6), Spain (n = 5), The Netherlands (n = 4), Denmark (n = 3), Norway (n = 3), Northern Ireland (n = 3), Belgium (n = 2), Canada (n = 2), China (n = 2), and France (n = 2), and one study each from Albania, Ecuador, Greece, Iceland, Ireland, Italy, Mexico, New Zealand, South Africa, and Switzerland. A range of ethnic groups was represented across trials; however, ethnicity was not reported in 40 of the 89 included studies. Most studies included both male and female students and reported a roughly even split between genders; one study included male students only, 11 included female students only, and 4 did not report the breakdown of male and female students.
Interventions
All studies had intervention components that were delivered in the school setting. Some projects provided additional interventions in the home, community, local theatre, or after school programmes, or via the computer. All studies included a control group that represented a school or a group of schools from a different community, city, or state that did not receive the school‐based intervention. However, in some studies, control schools received other physical activity promotion interventions provided through other health organisations or venues or by a standard PE curriculum. The duration of interventions varied greatly from a minimum of 12 weeks to 6 years, with 10 studies reporting intervention periods of 3 years or longer (Bush 1989; Daly 2016; Donnelly 2009; Donnelly 2017; Ickovics 2019; Luepker 1996; Simon 2004; Stone 2003; Walter 1988; Wang 2008). Several theoretical frameworks were used to develop the physical activity interventions, with some studies citing more than one framework. In 36 studies, it is unclear if a theoretical framework had been used to design and/or deliver the intervention. The most commonly cited theoretical models were social cognitive theory (n = 20), a socioecological model (n = 11), self‐determination theory (n = 10), and the theory of planned behaviour (n = 6). Studies reported in this review differed in funding levels, numbers of project staff, and resources available to deliver the programmes. Further, although all projects were primarily school based, no projects used the same combination of interventions with the same intensity, making each programme unique; however, some similarities were observed with respect to the ways in which interventions were delivered. Most commonly, interventions were multi‐component, whole‐school interventions that included a combination of educational materials, changes to the school environment, and/or school curriculum; and they targeted students, teachers, and/or parents (n = 40). Other interventions (n = 19) were focused primarily on providing opportunities for MVPA within school time, such as active academic lessons. All but one of these interventions targeted children rather than adolescents. Also common were interventions that enhanced the usual school PE programme (n = 15) by incorporating high‐intensity activity into PE classes or increasing the frequency or duration of PE classes. Finally, other interventions included additional opportunities for physical activity before school activities (such as walking groups), lunchtime physical activity programmes, or after school programmes within the school environment (n = 14). One study used a factorial design, comparing enhanced PE and/or an after school programme to usual school activities.
Comparisons
Across 89 trials, a total of 93 comparison groups were described, as each of four studies reported two comparison groups. Most often, investigators described the comparison group as continuing with normal school activities or regular school physical activity or PE without specifying what that might include (40 studies). Sixteen studies described what the typical physical activity in a school would be, which ranged from one PE class per week to two hours of PE per week. Thirteen comparison groups were simply described as ‘no intervention’ or participating only in data collection, with no indication of whether physical activity or PE was a part of the regular school setting. Ten studies described alternative or sham interventions, such as an alcohol and drug abuse prevention programme, with health screening only. One study used a spillover group as a second comparator group, which comprised students who were eligible but declined to participate in the intervention. The remaining 13 studies provided no description of the comparator group.
Outcomes
A protocol paper or trial registry was available for 59 of the 89 included trials; for the remaining 30 trials, a trial document was not identified. Within the 59 trial documents, a single primary outcome was specified in 38 trials; 17 trials documented multiple primary outcomes, and 4 trial documents did not specify a primary outcome. When a single primary outcome was stated, 17 were measures of MVPA, 8 were measures of BMI, 4 were measures of fitness, and 9 involved other endpoints, including other measures of body composition, academic achievement, feasibility, executive function, diabetes, and screen time.
Of the 55 studies that specified a primary outcome in their trial documents, 38 reported the same primary outcome in the publication, 12 specified a different primary outcome in the publication, and 5 did not specify a primary outcome in the publication at all.
Physical activity
A total of 38 of the 89 included trials reported some measure of activity using accelerometers. A number of different devices and protocols were used. Participants were asked to wear the accelerometer for anywhere from 3 to 9 days, but most often (n = 21), participants were asked to wear the accelerometer for 7 days. Three studies did not report accelerometer wear time. Most studies had participants wear the accelerometer for both weekday and weekend days (n = 29); however others recorded only weekday activity (n = 3), and 6 did not specify whether weekend days were included.
Five studies reported on the proportion of students who were physically active, and all studies used the criterion of reaching more than 60 minutes of MVPA per day. Each of two studies measured activity using the Actiheart and Actigraph accelerometers, and 1 used the GENEactive. The specific cut points used to classify activity as MVPA were not reported in 2 studies using the Actiheart (Adab 2018; Kobel 2014); different cut points were used in the other 3 studies using Actigraph and GENEactive accelerometers.
Of the 38 studies that reported on duration of MVPA, most used a model of Actigraph accelerometer (n = 26), and 7 did not report the type of accelerometer model used. Other models include the MTI (n = 2), Actiheart (n = 2), Minimeter (n=1), and GENEactive (n=1). The most commonly used cut points for classifying MVPA were Evenson cut points (17 studies), and 12 studies did not report the cut points used to classify MVPA. Across the remaining 9 studies, a variety of different cut points were reported.
Sedentary time
Sedentary time was measured via accelerometer in 20 studies. The most common cut points used to categorise time spent in sedentary behaviour were Evenson cut points of fewer than 100 counts per minute (n = 9); 6 studies did not specify the cut points used, and 5 studies reported other cut points.
Fitness
Objective physical fitness assessments were reported in 42 studies. Field‐based running tests were used most often, with 13 studies using the Progressive Aerobic Cardiovascular Endurance Run (PACER) test by Leger et al, and an additional 10 studies using a 20‐metre shuttle run protocol but not specifying whether it was the PACER protocol. Studies that used a shuttle run reported outcomes as number of laps completed, estimated VO₂max, age, and sex‐specific z‐scores for number of laps, highest level reached, and/or number of stages completed. Six studies reported using the Anderson 10‐minute interval test with distance run and estimated VO₂max as the outcome variable. One study used a 1‐kilometre run, 1 used a mile run, and 1 used a 9‐minute run protocol. Incremental treadmill tests with gas analysis were used in 3 studies, expressed as VO₂max, and 1 employed a peak power test on a cycle ergometer, expressed as Watts per kilogram of body mass. Last, 2 studies used the Queens College Step Test, 1 used the bench‐stepping test, 1 used the Harvard step test, 1 used the British Athletics Linear Track Test, and 1 used a 6‐minute run test.
Body mass index
Seventy‐one studies reported on BMI using objective measures. The most common expression of BMI, reported in 49 studies, was as kg/m². Three studies used country‐specific z‐scores (England and Germany), and 2 studies used German‐specific BMI percentile values. WHO z‐scores were used in 2 studies, Centers for Disease Control and Prevention z‐scores were used in 3 studies, and percentiles were used in an additional 3 studies. One study used the International Obesity Task Force cutoffs for weight status. Twelve studies used z‐scores but did not specify the source, 6 studies did not describe methods, and 1 study reported percentage body fat.
Health‐related quality of life
Only 7 studies reported some aspect of health‐related quality of life; a summary of the instruments used can be found in Appendix 5. Only one tool ‐ the Child Health Utility 9D ‐ was used in more than 1 study (Breheny 2020; Harrington 2018; Jago 2019).
Adverse events
Adverse events were not commonly reported in studies. Only 16 of 89 included studies provided any information about adverse events, most commonly to say that no adverse events were noted. Only 3 studies reported data about the number and nature of adverse events that occurred during the study in the intervention or control group.
Excluded studies
For this update, we excluded a total of 736 studies after full‐text review. The most common reason for exclusion was that trials were not randomised trials or trials did not include an objective measure of physical activity or physical fitness. Reasons for exclusion of studies from this update are available in the Characteristics of excluded studies table.
Risk of bias in included studies
For details on the risk of bias of included trials, see Characteristics of included studies and a summary across trials in Figure 2 and Figure 3.
Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included trials (blank cells indicate that the particular outcome was not measured in some trials).
Risk of bias summary: review authors' judgements about each risk of bias item for each included trial (blank cells indicate that the particular outcome was not measured in some trials).
Allocation
All included studies were RCTs, and a majority of included studies provided an adequate description of the methods used to generate the randomisation sequence (e.g. computer randomisation) and the methods used to conceal allocation from participants and personnel. Sixty‐seven of 89 studies adequately described randomisation sequence, 18 of 89 studies were unclear in their reporting, and 4 of 89 studies did not report an adequate method for creating the randomisation sequence and were described as high risk of bias in this domain. Sixty‐three of 89 studies adequately described allocation concealment, 15 of 89 were unclear or did not describe allocation concealment well, and in 11 of 89 studies, allocation concealment was not performed, introducing high risk of bias in this domain.
Blinding
The most notable methodological weakness of these studies is the lack of blinding of participants and personnel, with only 15 out of 89 studies adequately reporting that participants and study personnel were blinded to group allocation. This was primarily done by not informing participants about the overall goal of the study or the presence of other intervention arms. Blinding of participants and personnel was unclear in 17 of 89 studies, and in 57 of 89 studies, blinding of participants or personnel was not done, introducing high risk of bias in this domain. Adequate blinding of outcome assessors was described in 33 of 89 trials and was unclear in 22 of 89 trials. In 34 of 89 trials, outcome assessors were not blinded, introducing high risk of bias in this domain. All outcomes included in this review were objective measures and did not rely on self‐report, therefore reducing but not eliminating the potential for bias.
Incomplete outcome data
We assessed incomplete outcome data separately for physical activity and sedentary time outcomes and for physical fitness and anthropometric data. Among studies that assessed physical activity participation or duration, risk of bias due to incomplete outcome data was deemed low in 20 out of 40 studies, unclear in 4 of 40 studies, and high in 16 of 40 studies. Among studies that assessed sedentary time, 11 of 20 studies were deemed at low risk of bias for incomplete outcome data, 2 of 20 studies were unclear, and 7 of 20 studies had large quantities of missing data that introduced high risk of bias.
For studies that measured physical fitness, 23 of 42 studies were deemed at low risk of bias, 5 of 42 studies were unclear in their reporting of outcome data completion, and 14 of 42 had large quantities of missing data that introduced high risk of bias. Among studies that measured BMI, 40 of 74 studies were deemed at low risk of bias for completion of outcome assessment, 5 of 74 studies were unclear in the quantity of missing data, and 29 of 74 had large quantities of missing data that introduced high risk of bias.
Selective reporting
Forty‐six of 89 studies were deemed at low risk of bias for selective outcome reporting and reported on all of the outcomes specified in trial protocols or published protocol papers. Twenty‐nine studies were unclear in their selective outcome reporting, often because a protocol paper was not published, and 14 studies were deemed at high risk of bias for selective outcome reporting.
Other potential sources of bias
Cluster‐randomised trials
A total of 80 included trials were cluster‐randomised trials; therefore, risk of bias was appraised within four additional categories (recruitment bias, baseline imbalances, loss of clusters, and incorrect analysis). With respect to recruitment bias, 35 of 80 trials were deemed at low risk of bias, 13 were unclear in the timing of recruitment and randomisation, and 32 were at high risk of bias, often because schools or classes were aware of their intervention status prior to participant enrolment in the trial. With respect to baseline imbalance, 63 of 80 trials were deemed at low risk of bias, 11 of 80 were unclear, and 6 of 80 were deemed at high risk of bias. For loss of clusters, 54 out of 80 were deemed at low risk of bias, as they retained all clusters in the trials, 4 of 80 were unclear, and 22 were deemed at high risk of bias due to loss of clusters throughout the trial. Finally, with respect to incorrect analysis of cluster‐RCTs, 62 of 80 were deemed at low risk of bias, as they properly accounted for the clustered nature of the data in their statistical analysis, and 18 trials were deemed at high risk of bias for failing to incorporate clustering into their analyses.
Effects of interventions
See summary of findings Table 1.
Effects of school‐based physical activity interventions on primary outcomes
Physical activity participation
Overall, we are very uncertain about the effects of school‐based physical activity programmes on the proportion of students meeting physical activity guidelines due to inconsistency of effects between studies, imprecision around the effects, and risk of bias in the included studies contributing to this outcome.
This outcome was reported in only 5 studies with quite different interventions (Analysis 1.1). One study explored the effects of after school dance classes on the proportion of girls meeting physical activity guidelines (Jago 2015). At the end of the 20‐week study, between‐group differences in adherence to guidelines were found to be ‐1.11% (95% confidence interval (CI) ‐1.68 to ‐0.73) in the intervention group compared to the control group. One study found that although both groups had fewer adolescents meeting guidelines at the end of study, the decline was noted to be smaller in the intervention group than in the control group; however confidence intervals were not reported (difference 12.22%; P < 0.01) (Andrade 2014). Another study found an uncertain effect on the odds of meeting the guidelines in the intervention group compared to the control group at end of study (odds ratio (OR) 0.65, 95% CI 0.23 to 1.85) (Harrington 2018). One study found a similar proportion of students meeting the guidelines at 15 or 18 months following a whole‐school physical activity and nutrition intervention (difference at 15 months 0.005%, 95% CI ‐0.101 to 0.140) (Adab 2018). One study found that after one year, differences in the proportion of participants meeting guidelines between intervention and control groups were 10.4%; study authors noted that the difference between groups was not statistically significant but included no measure of variation (Kobel 2014).
Physical activity duration
Overall, school‐based physical activity interventions probably have little to no effect on minutes per day of MVPA among children and adolescents (mean difference (MD) 0.73, 95% CI 0.16 to 1.30; 33 studies; Analysis 1.2 moderate‐certainty evidence). These findings should be interpreted with caution due to the inconsistency in outcomes reported based on visual inspection of forest plots and substantial heterogeneity across studies (I² = 75%).
Six additional studies provided data that were not included in the meta‐analysis. Most findings were consistent with results from the meta‐analysis (Analysis 1.4). Following one year of PE enhanced with strength training and motivational interviewing among adolescents, a significant between‐group difference was found in the percentage of time spent in MVPA; however, the magnitude of this difference was not reported (Ten Hoor 2018). In a study of Grade 7 students, those who took part in a biweekly after school PA programme, enhanced PE, or both were found to increase the percentage of time spent in MVPA (MD 1.99%, 95% CI 1.68 to 2.30; MD 3.12%, 95% CI 2.76 to 3.48; MD 4.98%, 95% CI 4.62 to 5.34, respectively), which was noted by study authors as statistically significant (Zhou 2019).
In one study, changes in vigorous activity were reported from an intervention targeting behavioural modification (MD 2.8 minutes/d, 95% CI 0.3 to 5.4) or fundamental movement skills (MD 7.8 minutes/d, 95% CI 3.4 to 12.3 minutes/d), and combining behavioural modification and fundamental movement skills (MD 3.1 minutes/d, 95% CI ‐0.58 to 6.7) compared to control (Salmon 2008). Grade 2 children who engaged in physical activity during school, lessons, and recess were noted to take part in more MVPA at study midpoint but not at the end of the intervention; values were not reported (Magnusson 2011). Following implementation of a brisk walking programme during the school day, moderate to vigorous accelerometer counts were reported in the intervention group compared to a control group (MD ‐27.4 counts/min, 95% CI ‐91.0 to 36.2) (Ford 2013). Finally, within‐school and between‐school pedometer step challenges among adolescents age 12 to 14 years were found to be feasible, but minutes/d of MVPA appeared stable across groups throughout the intervention periods (MD ‐14.4 minutes/d, no measure of variance reported) (Corepal 2019).
In subgroup analyses, no differences in effects were found between interventions targeting children and adolescents (test for subgroup differences, P = 0.35; Analysis 1.2); however there were subgroup differences by intervention type (test for subgroup difference, P = 0.03; Analysis 1.3).
Children
In subgroup analyses, school‐based physical activity interventions targeting children probably do not result in a meaningful change in minutes per day of MVPA (MD 1.01 minutes/d, 95% CI 0.08 to 1.93; 22 studies; Analysis 1.2 moderate‐certainty evidence). These findings should be interpreted with caution due to substantial heterogeneity across studies (I² = 69%). Across studies that were not included in the meta‐analysis, findings were consistent (Analysis 1.4).
Adolescents
School‐based physical activity interventions probably do not result in a meaningful change in minutes per day of MVPA among adolescents (MD 1.84 minutes/d, 95% CI 0.34 to 3.35; 11 studies; Analysis 1.2; moderate‐certainty evidence), with substantial heterogeneity (I² = 81%); when differences were found, they were generally small in magnitude (Analysis 1.4).
Before and after school programmes
A total of 6 included studies implemented before and after school programmes in the school setting. Overall, before and after school programmes probably do not increase time spent in MVPA (MD 0.77 minutes/d, 95% CI ‐1.40 to 2.94; 6 studies; Analysis 1.3; moderate‐certainty evidence). Moderate heterogeneity was found across studies (I² = 50%).
Enhanced PE
Three studies tested the effects of enhanced PE interventions. These interventions probably do not change MVPA (MD ‐0.23 minutes/d, 95% CI ‐1.58 to 1.11; 3 studies; Analysis 1.3; moderate‐certainty evidence); however results should be interpreted with caution due to high heterogeneity (I² = 83%).
Multi‐component interventions
Multi‐component interventions in the school setting probably result in small increases in MVPA among children and adolescents (MD 2.42 minutes/d, 95% CI 0.62 to 4.22; 16 studies; Analysis 1.3; moderate‐certainty evidence); however results should be interpreted with caution due to high heterogeneity (I² = 76%).
Schooltime PA
Schooltime PA interventions probably do result in small increases in MVPA among children and adolescents (MD 5.30 minutes/d, 95% CI 0.89 to 9.72; 8 studies; Analysis 1.3; moderate‐certainty evidence); however results should be interpreted with caution due to high heterogeneity (I² = 73%).
Sedentary time
Identified evidence suggests that school‐based physical activity interventions may have little to no difference in minutes per day of sedentary time (MD ‐3.78 minutes/d, 95% CI ‐7.80 to 0.24; 16 studies; Analysis 1.5; low‐certainty evidence). These findings should be interpreted with caution due to imprecision of the effect estimate and risk of bias of included studies.
Four additional studies provided data that were not included in the meta‐analysis. A majority of findings were consistent with meta‐analysis results, finding little or no effect (Analysis 1.7). Three studies reported sedentary time as an outcome within enhanced PE interventions in adolescents. In a study of teacher PE training, the between‐group mean difference in time spent sedentary at 7 months was 0.92% (95% CI ‐0.28 to 2.13) and was 0.02% (95% CI ‐0.99 to 0.95) at 14 months (Lonsdale 2019a). After one year of strength training and motivational interviewing, study authors note no statistically significant decrease in the percentage of time spent sedentary; however only P values were reported (Ten Hoor 2018). In a study of Grade 7 students, the change in percentage of time spent sedentary among those who took part in a biweekly after school PA programme, enhanced PE, or both was found to be 1.34% (95% CI ‐0.73 to 3.41), 1.11% (95% CI ‐1.09 to 3.31), and 0.11% (95% CI ‐2.31 to 2.54), respectively (Zhou 2019). Finally, within‐school and between‐school pedometer step challenges in adolescents age 12 to 14 years were found to be feasible, but sedentary time appeared stable across groups throughout intervention periods (MD 1.2 minutes/d; no measure of variance reported) (Corepal 2019).
In subgroup analyses, no differences in effects were found between children and adolescents (test for subgroup differences, P = 0.58; Analysis 1.5) or by intervention type (test for subgroup difference, P = 0.58; Analysis 1.6).
Children
Overall, school‐based physical activity programmes may not reduce sedentary time among children (MD ‐3.35 minutes/d, 95% CI ‐9.30 to 2.60; 11 studies; Analysis 1.5; low‐certainty evidence), with low heterogeneity of 37% (Analysis 1.5).
Adolescents
School‐based physical activity programmes may result in little to no difference in sedentary time of adolescents (MD ‐5.67 minutes/d, 95% CI ‐11.48 to 0.14; 5 studies; Analysis 1.5; low‐certainty evidence), with no heterogeneity observed (I² = 0%) (Analysis 1.5).
Before and after school programmes
Before and after school programmes in the school setting may not decrease sedentary time (MD 2.01 minutes/d, 95% CI ‐15.28 to 19.31; 2 studies; Analysis 1.6; low‐certainty evidence). Moderate heterogeneity was found across studies (I² = 46%).
Enhanced PE
Only one study explored the impact of enhanced PE on sedentary time (MD ‐11.18 minutes/d, 95% CI ‐21.96 to ‐0.40; 1 study; Analysis 1.6; low‐certainty evidence).
Multi‐component interventions
Multi‐component interventions in the school setting may result in small decreases in sedentary time (MD ‐4.60 minutes/d, 95% CI ‐9.08 to ‐0.12; 11 studies; Analysis 1.6; low‐certainty evidence). No heterogeneity was noted (I² = 0%).
Schooltime PA
Schooltime PA interventions may not decrease sedentary time (MD ‐3.26 minutes/d, 95% CI ‐19.05 to 12.52; 2 studies; Analysis 1.6; low‐certainty evidence); however results should be interpreted with caution due to the small number of studies and high heterogeneity (I² = 70%).
Effects of school‐based physical activity interventions on secondary outcomes
Fitness
Evidence suggests that school‐based physical activity programmes may improve physical fitness assessed by measured or estimated VO₂max (MD 1.19 mL/kg/min, 95% CI 0.57 to 1.82; 13 studies; Analysis 1.8; low‐certainty evidence). These findings should be interpreted with caution due to inconsistency in effect estimates (based on the high level of heterogeneity in the meta‐analysis (I² = 90%) and visual inspection of forest plots) and indirectness in measuring fitness using estimated VO₂max in most studies.
Twenty‐nine additional studies provided data that were not included in the meta‐analysis. Most results were consistent with the direction of the pooled effect (Analysis 1.10).
Four studies explored the impact of before and after school physical activity interventions. One study found an improvement in shuttle run performance with MD of 3.87 laps (standard error (SE) 1.51; P = 0.012) laps following 12 weeks of health education and after school physical activity (de Heer 2011). In a second study, the authors noted a statistically significant improvement in heart rate response to a step test after the ‘FitKid’ after school physical activity programme, although absolute values were not reported (Wang 2008). In a study of a brisk walking intervention delivered to adolescents, authors reported that the intervention had little to no effect on fitness (Carlin 2018); however no values for physical fitness were reported. In another study, a bi‐weekly after school programme on its own or combined with enhanced PE yielded statistically significant improvement in shuttle run performance in both intervention groups (MD 8.86 laps, 95% CI 5.68, 12.04 and 22.26 laps; 95% CI 19.15 to 25.37, respectively) (Zhou 2019).
Five studies investigated the effects of enhanced PE on the fitness of school‐age children. Following 12 weeks of adding a daily run to regular physical activity, between‐group difference in 1‐km run time was MD ‐0.55 minutes (95% CI ‐0.75 to ‐0.35) (Ordóñez Dios 2019). An additional 120 minutes/week of supervised PE resulted in a between‐group difference in shuttle run stages of MD 0.36 stages (95% CI 0.23 to 0.49) (Thivel 2011). One study found that two additional 45‐minute PE lessons per week resulted in a between‐group difference in stages on the shuttle run test favouring the control group (MD ‐0.12 stages, 95% CI ‐0.21 to ‐0.03) (Kriemler 2010). After 12 weeks of high‐intensity interval training, between‐group difference in z‐scores in Grade 3 students was MD 7.7 (95% CI 2.3 to 13.2) (Ketelhut 2020). In another study, enhanced PE on its own or combined with a biweekly after school programme yielded statistically significant improvement in shuttle run performance in both intervention groups (MD 14.33 laps, 95% CI 11.16 to 17.50; and MD 22.26 laps, 95% CI 19.15 to 25.37, respectively) (Zhou 2019).
Eleven studies explored the effects of multi‐component interventions. After 12 months of teacher learning, physical activity policies, and school community linkages, MD of 5.4 laps (95% CI 2.3 to 8.6) was found in children (Cohen 2015). A one‐year multi‐component intervention resulted in between‐group differences among students in Grades 3 to 5 of 0.57 laps (95% CI 0.13 to 1.01) and in Grades 6 to 8 of 0.04 laps (95% CI ‐0.45 to 0.53) (Jansen 2011). Following a 9‐month intervention, study authors reported that the number of laps completed by children on the shuttle run significantly increased in the intervention group versus the control group, but values were not reported (Burke 1998). After 11 months of a whole‐school physical activity programme, between‐group difference in shuttle run laps in intervention versus control groups was +6 laps (95% CI 1.6 to 10.4) (Reed 2008). In one study, authors reported that the difference in change in shuttle run performance at 2.5 years was 0.2 laps (95% CI ‐0.5 to 0.9) following a multi‐component intervention for children consisting of education, social marketing, changes to the food environment, and PE curriculum (Jago 2011). One study reported that physically active lessons, physically active homework, and physically active recess resulted in within‐group differences in laps in the control group (m 5.8, SE 0.4) and in the intervention group (m 4.7, SE 0.4), with a between‐group MD of ‐1.1 (95% CI ‐2.2 to 0.01) favouring the control group (Seibert 2019). Following an intervention with environmental and policy‐level changes, study authors reported no statistically significant differences in distance covered during a nine‐minute run test; however absolute values were not reported (Aburto 2011). Following two years of nutrition education, Playworks structured recess, and before and after school activities, the between‐group difference in mile run time was MD 0.2 minutes (95% CI ‐0.8 to 0.4) (Madsen 2015). After 28 months of individual‐ and environmental‐based interventions, between‐group difference in time during a shuttle run for adolescents was MD ‐0.19 minutes (95% CI ‐0.54 to 0.16) (Andrade 2014). Following seven months of health programming and health messaging targeting diabetes control and goal‐setting, between‐group difference in Harvard Step Test scores was MD 1.87 points (95% CI ‐1.44 to 5.17; P = 0.04) (Trevino 2004). Last, the mean difference in shuttle run test distance between adolescents in schools that underwent physical and organisational environmental changes and a control group was MD 6 metres (95% CI ‐20 to 31 after two years of follow‐up) (Toftager 2014).
Finally, ten studies reported on the impact of schooltime PA interventions. Following 12 months of the Daily Mile programme, results favoured the control group (MD ‐37.4 metres, 95% CI ‐74.7 to ‐0.19) (Breheny 2020). Study authors noted that shuttle run performance increased by 0.8 laps in both intervention and control groups after two years of physically active math and language lessons (MD 0.05 stages, SE 0.14; not statistically significant) (de Greeff 2016). After three years of physically active lessons, mean difference in shuttle run test was 1.3 laps (95% CI ‐0.5 to 3.1) (Donnelly 2017). One study found that active math lessons delivered over one 10‐month school year resulted in mean difference in shuttle run test distance of 10 metres (SE 13.9; P > 0.05) (Have 2018). An intervention including 60 minutes of physical activity during school time and physical activity homework found a between‐group difference in shuttle run distance of MD 9.4 metres (95% CI ‐3.7 to 22.4) at 20 weeks (Tarp 2016). An intervention consisting of 7 months of physical activity lessons, homework, and breaks found MD 6.9 metres (95% CI ‐8.9 to 22.6) (Resaland 2016). After 22 weeks of using cycling desks in the classroom, the mean difference in 20‐metre shuttle run was 0.5 stages (95% CI ‐0.5 to 1.5) (Torbeyns 2017). After two years of active physical activity, PE lessons, classroom physical activity, and additional physical activity equipment and teaching materials, the mean difference in maximal cycling test output was 0.37 watts/kg (95% CI ‐0.27 to 1.01) (Magnusson 2011). Physically active lessons, active homework, and recess did not produce a statistically significant effect, although no data were reported (Seljebotn 2019). Finally, 14 weeks of high‐intensity interval training resulted in a mean difference of 8.9 laps (95% CI 1.7 to 16.2) at 14 weeks (Leahy 2019).
In subgroup analyses, no differences in effects were found between children and adolescents (test for subgroup differences, P = 0.08; Analysis 1.8). Differences in effects by intervention type were noted (test for subgroup difference, P < 0.001; Analysis 1.9).
Children
Overall, evidence suggests that school‐based physical activity programmes probably improve physical fitness among children (MD 1.47 mL/kg/min, 95% CI 0.84 to 2.09; 9 studies; Analysis 1.8 moderate‐certainty evidence). However, this should be interpreted with caution, as only 9 of 31 included studies reported sufficient data to be included in the meta‐analysis. Moderate heterogeneity was also noted across trials (I² = 64%).
Adolescents
Generally, school‐based physical activity programmes probably result in little to no difference in physical fitness (Analysis 1.10). Pooled analysis from studies that reported VO₂max revealed no difference (MD 0.58 mL/kg/min, 95% CI ‐0.18 to 1.35; 4 studies; moderate‐certainty evidence; moderate heterogeneity (I² = 87%).
Before and after school programmes
Before and after school programmes in the school setting probably improve physical fitness (MD 1.38 mL/kg/min, 95% CI 0.34 to 2.41; 5 studies; Analysis 1.9 moderate‐certainty evidence). High heterogeneity was found across studies (I² = 88%).
Enhanced PE
Studies that enhanced PE as part of the intervention probably resulted in improvements in physical fitness (MD 1.99 mL/kg/min, 95% CI 0.76 to 3.21; 4 studies; Analysis 1.9 moderate‐certainty evidence); however high heterogeneity was found across studies (I² = 82%).
Multi‐component interventions
Multi‐component interventions in the school setting probably do not change physical fitness (MD ‐0.33 mL/kg/min, 95% CI ‐0.73 to 0.08; 3 studies; Analysis 1.9 moderate‐certainty evidence); however results should be interpreted with caution due to the small number of studies. No heterogeneity was noted (I² = 0%).
Schooltime PA
Only one study that used schooltime PA to increase fitness was included in the meta‐analysis (MD 2.70, 95% CI 1.04 to 4.36; 1 study; Analysis 1.9); thus, results should be interpreted with caution.
Body mass index
Overall, evidence suggests that school‐based physical activity programmes may result in a very small decrease in BMI z‐score among children and adolescents (MD ‐0.06, 95% CI ‐0.09 to ‐0.02; 21 studies; Analysis 1.11 low‐certainty evidence) and may not decrease BMI (MD ‐0.07 kg/m², 95% CI ‐0.15 to 0.01; 50 studies; Analysis 1.13 low‐certainty evidence). These results should be considered with caution, as substantial heterogeneity and risk of bias were found across studies.
Nine additional studies provided data that could not be included in the meta‐analysis. Findings were mixed. After a 9‐month multi‐component intervention, study authors reported that BMI decreased among boys in the intervention group versus the control group, but not among girls; values were not reported (Burke 1998). After 3 years of a physical activity or physical activity and nutrition wellness policy, study authors found no differences in children's BMI; however values were not reported (Ickovics 2019). Between‐group differences were reported in children's BMI/age‐sex population median values following an intervention targeting behavioural modification (MD ‐0.40, 95% CI ‐1.11 to 0.30), fundamental movement skills (MD ‐0.50, 95% CI ‐1.25 to 0.25), or both (MD ‐1.30, 95% CI ‐2.29 to ‐0.31) (Salmon 2008). After 3 years of physically active lessons, the difference in BMI percentile between intervention and control groups was MD ‐2.3 (95% CI ‐4.8 to 0.2) (Donnelly 2017). After 1 year of active breaks during class time, the between‐group difference in BMI percentile was 0.5 (95% CI ‐0.5 to 1.5) (Kobel 2014). A 2‐year intervention to increase schooltime PA also yielded a between‐group difference in BMI that was not statistically significant, and effect estimates were not reported (Williamson 2007). A 12‐week brisk walking intervention for adolescents produced no difference, but effect estimates were not reported (Carlin 2018). A 16‐week intervention consisting of enhanced PE or enhanced PE with a focus on increasing intensity had no impact on BMI in adolescents, with no values reported (Ardoy 2011). Last, a 1‐year multi‐component intervention for adolescents resulted in a mean difference in BMI percentile of MD 1.09 (95% CI ‐0.64 to 2.82) (Suchert 2015).
In subgroup analyses, no differences in effects were found between children and adolescents for BMI z‐scores (test for subgroup differences, P = 0.23; Analysis 1.11) nor for BMI (test for subgroup differences, P = 0.19; Analysis 1.13). In subgroup analyses by intervention type, no differences in effects were found between intervention types for BMI z‐scores (test for subgroup differences, P = 0.61; Analysis 1.12) nor for BMI (test for subgroup differences, P = 0.80; Analysis 1.14).
Children
School‐based physical activity interventions for children may decrease BMI z‐scores; MD ‐0.06 (95% CI ‐0.11 to ‐0.01; 16 studies; substantial heterogeneity of 88%; Analysis 1.11; low‐certainty evidence). These interventions may also result in a small decrease in BMI (MD ‐0.11 kg/m², 95% CI ‐0.19 to ‐0.02; 38 studies; substantial heterogeneity of 84%; Analysis 1.13; low‐certainty evidence).
Adolescents
School‐based physical activity interventions for adolescents may not decrease BMI z‐scores (MD ‐0.03, 95% CI ‐0.05 to ‐0.00; 5 studies; I² = 0%; Analysis 1.11 low‐certainty evidence) nor BMI (MD 0.05 kg/m², 95% CI ‐0.16 to 0.25; 12 studies; I² =88%; Analysis 1.13 low‐certainty evidence).
Before and after school programmes
Before and after school programmes in the school setting may not decrease BMI z‐scores (MD ‐0.02, 95% CI ‐0.05 to 0.01; 2 studies; Analysis 1.12 low‐certainty evidence) nor BMI (MD ‐0.12 kg/m², 95% CI ‐0.25 to 0.01; 9 studies; Analysis 1.14 low‐certainty evidence). Very little heterogeneity was found across studies (I² = 0%, 7%, respectively).
Enhanced PE
Studies that enhanced PE as part of the intervention may not decrease BMI z‐scores (MD ‐0.08, 95% CI ‐0.29 to 0.13; 1 study; Analysis 1.12 low‐certainty evidence) nor BMI (MD ‐0.04 kg/m², 95% CI ‐0.32 to 0.24; 10 studies; Analysis 1.14 low‐certainty evidence). Results should be interpreted with caution, as only one study reported changes in BMI z‐scores, and high heterogeneity was found across studies for BMI (I² = 92%).
Multi‐component interventions
Multi‐component interventions in the school setting may result in small decreases in BMI z‐scores (MD ‐0.06, 95% CI ‐0.11 to ‐0.01; 17 studies; Analysis 1.12 low‐certainty evidence) but not in BMI (MD ‐0.10 kg/m², 95% CI ‐0.24 to 0.03; 20 studies; Analysis 1.14 low‐certainty evidence). In both analyses, high heterogeneity was found across studies (I² = 87%, 93%, respectively).
Schooltime PA
Only one study reported on the effect of schooltime PA on BMI z‐score (MD ‐0.03, 95% CI ‐0.08 to 0.02; 1 study; Analysis 1.12 low‐certainty evidence). Schooltime PA may not decrease BMI (MD ‐0.05 kg/m², 95% CI ‐0.14 to 0.04; 11 studies; Analysis 1.14 low‐certainty evidence). Low heterogeneity was found across studies.
Health‐related quality of life
Seven included studies reported on health‐related quality of life (Analysis 1.16). Given the limited data reported across heterogeneous interventions and populations, as well as the risk of bias in included studies and possible reporting bias in studies that did not report results for this outcome, we are very uncertain about the effects of school‐based physical activity interventions on health‐related quality of life. A full description of the scales used to assess health‐related quality of life can be found in Appendix 5.
One study reported a decrease in perceived psychological difficulties among adolescents after 14 weeks of high‐intensity interval training compared to those in a control group (MD ‐2.1 points, 95% CI ‐4.0 to ‐0.3) as measured by the Strengths and Difficulties Questionnaire (Leahy 2019). A school‐based physical activity and healthy eating programme noted a mean difference of 1.248 (95% CI ‐2.301 to 4.796) in paediatric quality of life as measured by the Pediatric Quality of Life inventory (Adab 2018). An after school dance programme noted a mean difference in health‐related quality of life of 0.0 points (P = 0.667) when using the European Quality of Life 5 Dimensions Youth Survey (Jago 2015). The Daily Mile intervention resulted in a between‐group difference of 0.010 points (95% CI ‐0.002 to 0.04) after 12 months on the Child Health Utility 9D, where higher scores indicate poorer health (Breheny 2020). The remaining three studies reported no statistically significant differences between groups and provided no data (Harrington 2018; Jago 2019; Resaland 2016).
Adverse events
Of the 89 trials included, only 16 reported anything related to adverse events (Analysis 1.17). Based on limited data on adverse events reported, including inconsistency between studies, high risk of bias, and the possibility of reporting bias in studies that did not report results for this outcome, the evidence is of very low certainty; we cannot confidently conclude whether there are or are not potential safety concerns related to school‐based physical activity interventions. Of the studies that noted adverse events, 13 simply stated that no adverse events occurred as part of the intervention. Often minimal detail was given as to how adverse events were tracked or recorded. Adverse events were reported in three studies. In one study, a minor adverse event occurred when an intervention participant made contact with another participant while doing a handstand (Nogueira 2014). Another study reported adverse event rates across both study groups of 2.4% at baseline and 1.7% at end of study related to a blood draw for data collection (Jago 2011). The most commonly reported adverse event was dizziness and was not deemed to be related to the intervention itself. Finally, one study reported 24 adverse events such as musculoskeletal injuries; 20 were deemed to be mild, three moderate, and one serious, for an overall adverse event rate of 0.0006 events per programme hour (Wang 2008).
Assessment of reporting bias
To assess the potential for reporting bias, we created funnel plots for MVPA, sedentary time, fitness, and BMI reported in kg/m² and z‐scores (Figure 4, Figure 5, Figure 6, Figure 7, Figure 8). Because we used a random‐effects meta‐analysis, 95% confidence intervals are not calculated via RevMan 5.4. Based on our interpretation of the funnel plots, it appears there may be some degree of reporting bias in studies that report on minutes per week of MVPA. This reporting bias may lead to overestimation of the magnitude of the effect; however given the overall null findings of the meta‐analysis, this does not change our conclusions.
Funnel plot of comparison: 1.2 Physical activity duration: meta‐analysis.
Funnel plot of comparison: 1.5 Sedentary time: meta‐analysis.
Funnel plot of comparison: 1.8 Physical fitness: meta‐analysis.
![Funnel plot of comparison: 1.11 BMI: meta‐analysis [z‐scores].](/cdsr/doi/10.1002/14651858.CD007651.pub3/media/CDSR/CD007651/image_n/nCD007651-FIG-07.svg)
Funnel plot of comparison: 1.11 BMI: meta‐analysis [z‐scores].
![Funnel plot of comparison: 1.13 BMI: meta‐analysis [kg/m2].](/cdsr/doi/10.1002/14651858.CD007651.pub3/media/CDSR/CD007651/image_n/nCD007651-FIG-08.svg)
Funnel plot of comparison: 1.13 BMI: meta‐analysis [kg/m2].
Trials ongoing and awaiting classification
Within our search, we identified 16 trials that are awaiting classification (Characteristics of studies awaiting classification), as well as 12 studies that are ongoing (Characteristics of ongoing studies). Within the studies awaiting classification, 12 are marked as ‘complete’ in the clinical trials registry, but no publications can be found; one has been published only as a protocol paper (Friedrich 2015); two have published conference abstracts but with insufficient information to determine eligibility (O'Malley 2011; Telford 2019); and one has published baseline results only (Salmon 2011a). Within the 9 ongoing studies, trial start dates ranged from 2014 to 2018, with planned end dates from 2020 to 2022. Three studies did not indicate a planned end date.
Discussion
Summary of main results
The objective of this updated review was to assess, analyse, and draw conclusions about the effectiveness of school‐based interventions in promoting physical activity and fitness among school‐attending children and adolescents aged 6 to 18 years. Our primary outcomes were physical activity and sedentary time, with secondary outcomes of fitness, body composition, health‐related quality of life, and adverse effects. Finally, through subgroup analyses, we sought to identify which types of interventions may be most effective for improving physical activity, fitness, and body mass index (BMI) in this population.
The results of this update do not differ greatly from those reported in the original review in 2009 and in the update in 2013. Overall, school‐based physical activity interventions may improve physical fitness (low‐certainty evidence) but probably have minimal impact on time engaged in moderate to vigorous physical activity (MVPA) (moderate‐certainty evidence) and may result in little to no decrease in sedentary time (low‐certainty evidence). Although school‐based physical activity interventions may result in a small decrease in BMI z‐scores (low‐certainty evidence), they may not impact BMI measured as kg/m² (low‐certainty evidence). In this version of the review, only objective measures of physical activity, sedentary time, fitness, and BMI were included. This is important progress, as the advantages of objectively measured physical activity and sedentary time outweigh the advantages of self‐report measures of these outcomes. In addition, the commercialisation of these devices means the costs of these devices are no longer as prohibitive as they once were. The original review and the 2013 update found that school‐based physical activity interventions had a small positive impact on duration of MVPA and television viewing; however, these systematic reviews primarily measured activity using self‐report measures completed by children, parents, or teachers, which may have introduced substantial bias into the results.
We are uncertain as to the effects of school‐based physical activity interventions on the proportion of children or adolescents who met the physical activity guidelines recommendation of 60 minutes of daily MVPA. Some studies report that multi‐component interventions increase the proportion of adolescents meeting guidelines; however, only 2 studies reported on this outcome, and more work is needed to increase the certainty of these findings. When MVPA was reported in minutes/d, little to no difference was seen in the duration of MVPA among children and adolescents. When separated by the type of intervention implemented, some evidence suggests that schooltime physical activity programmes and multi‐component interventions may result in larger increases in MVPA. This is a new finding from our 2013 review, which did not examine effects separately by the type of intervention implemented due to the smaller number of studies. Except for multi‐component interventions, which may result in a small decrease in sedentary time, school‐based physical activity programmes do not appear to be effective in reducing sedentary time among both children and adolescents.
In contrast, school‐based physical activity interventions may have a small to moderate effect on physical fitness among both children and adolescents. In particular, enhanced physical education (PE) and before and after school programmes may result in the largest gains in fitness. Interventions that focused specifically on increased exercise intensity (such as high‐intensity interval training ‐ Leahy 2019 ‐ and an enhanced PE intervention with a specific focus on increased exercise intensity ‐ Ardoy 2011) led to the largest effect sizes.
Although BMI was the most reported outcome, school‐based physical activity interventions may result in a small decrease when measured as z‐scores, and little to no difference when measured as kg/m². Although many of the multi‐component interventions did include additional components such as nutrition education or changes to the school food environment, a more specific focus on diet and nutrition both inside and outside the school environment may be needed to change body weight trajectories (Ho 2012; Ho 2013). Notably, in this update, interventions that were targeted primarily at improving body composition without an explicit focus on physical activity or physical fitness were excluded.
The 2013 review found limited evidence that positive effects are maintained in the longer term, although only a small number of studies measured outcomes beyond the end of the intervention. In this version, several studies reported long‐term follow‐up, but evidence to suggest that changes were maintained long term remains limited. One limitation of this update is that we explored impact only at the immediate post‐intervention time period due to wide heterogeneity in follow‐up times across interventions. The wide variety of study designs, lengths of intervention, and lengths of follow‐up make it challenging to further comment on sustainable effects of the interventions. As more data become available, future updates may have access to sufficient data to pool effects from studies with longer follow‐up time periods.
Very few studies reported on differences in response to interventions between boys and girls, and these results were mixed in with results of studies that did report these differences. As such, we did not seek to carry out a subgroup analysis on differential effects in boys versus girls. Recent estimates suggest there are meaningful differences in physical activity levels between boys and girls, and that although prevalence of insufficient physical activity decreased from 2001 to 2016 in boys, no such change occurred among girls (Guthold 2020). Future studies in this field should examine results separately for boys and girls to determine if interventions have similar effects in individuals of both genders.
Finally, few studies reported information about adverse events, or how these were identified and captured. Adverse events reported were generally muscle soreness or injury related to physical activity and bruising related to a data collection blood draw, for example. One systematic review on physical activity and health outcomes related to physical activity interventions overall reported that no included studies reported any harm or injury associated with physical activity participation (Poitras 2016). These types of potential harms should be explored and reported clearly in future school‐based trials.
One aspect not often considered is the potential for adverse effects on quality of life or harms related to the stigma of participating in physical activity with their peers at school. Also missing from most studies was consideration of factors related to health equity. If physical activity or physical education programming does not meet the needs of individual students or certain subgroups of students, participation may be limited, which may be reflected in variation in findings across studies. In a review of studies about meaningful experiences in physical education and sport, identified themes were social interaction, fun, challenge, competition, motor competence, and personally relevant experiences (Beni 2017). Negative experiences reported in physical education classes in childhood were related to embarrassment and lack of enjoyment of fitness testing and sport, and positive memories of school physical education, such as enjoyment of class activities, time spent with friends or outside, or being allowed to move more after sitting in class all day, were associated with positive attitudes and intentions to be physically active in adulthood in another study (Ladwig 2018). These studies suggest that students need to identify personal meaning in their school physical activity opportunities; a “one‐size‐fits‐all” approach may not be appropriate to encourage physical activity participation.
Most studies did not comment on aspects related to implementation of interventions, such as uptake or adherence to the interventions and fidelity of delivery. It is unknown if interventions were successfully delivered within the schools, which can often be challenging. Without an understanding of fidelity of delivery, any additional minutes of MVPA that resulted from taking part in the school‐based intervention could be compensated for by a decrease in MVPA outside of school time; thus, no overall change in full‐day MVPA was observed. Also, failure to properly implement the programme and poor adherence to the intervention at the student level may occur. Finally, although patient‐oriented research and community engagement initiatives are becoming increasingly prevalent in adult research literature, youth engagement in both design and implementation of these interventions may prove to be a useful strategy to promote uptake and adherence. This could in turn result in not only more meaningful improvements in these short‐term behaviours but also a long‐term commitment to physical activity to improve health and reduce chronic disease risk into adulthood.
Overall completeness and applicability of evidence
A comprehensive search of randomised controlled trials (RCTs) and cluster‐RCTs was conducted, and it is unlikely that many studies were missed by our search strategy. Studies included in this review are applicable to public health and education in high‐income countries, as most studies were conducted in the USA, the UK, and Australia; different strategies may be needed and different effects may be found in low‐ to middle‐income countries. Most studies included in this review were conducted in school‐age children (ages 6 to 12); a smaller number were conducted in adolescents. Although ten trials were conducted exclusively in female students, only one study was conducted among boys only, and few trials explored the effects of sex and gender in the analysis.
The types of interventions included varied widely, and no two studies implemented the same interventions. This makes it very challenging to draw conclusions as to the most effective components of interventions that can elicit changes in the outcomes of interest. The benefit of the wide variety of interventions is that researchers and policy makers can search a variety of protocols to determine what might be effective for future interventions or programming.
Although RCTs are considered the gold standard design for exploring efficacy, it is possible that inclusion of non‐randomised intervention studies may have provided more information on outcomes that were important to this review, namely, health‐related quality of life and adverse events. Given the large number of included trials, it is not feasible to include non‐randomised evidence in this update. However, we wish to acknowledge the potential for this information to be included in studies that were not captured in this review.
Quality of the evidence
As outlined, several factors limited the certainty of results in this review. The most common reason why certainty was downgraded was inconsistency, assessed through visual inspection of forest plots and I² values from the meta‐analysis. This criterion for downgrading was applied to all outcome measures except for sedentary time. Inconsistency in findings is not surprising, given the large differences in target populations, components of interventions studied (including dose and type of physical activity), ways in which outcomes were assessed, and time periods of follow‐up. Nonetheless, this inconsistency limits our confidence in the effects of school‐based physical activity interventions overall.
The quality of the evidence was also limited by high or uncertain risk of bias in the included studies. Although all included trials were individually randomised or cluster‐randomised trials, a number of methodological limitations were present. In particular, blinding of participants and personnel and of outcome assessors often was not reported, introducing the potential for performance and detection bias in assessment of results. Due to the nature of school‐based physical activity interventions, it is near impossible to blind participants and personnel to the assigned intervention. However, blinding of outcome assessors and data analysts is important and could be improved upon in future studies. Attrition bias was also prevalent across studies, particularly for measures of physical activity and sedentary time. Some loss to follow‐up is unavoidable in school‐based interventions, and study authors often reported the proportion of students lost to follow‐up due to moving and changing schools. However, often a greater proportion of missing data was related to physical activity or sedentary time measured by accelerometers. Adherence to wear time protocols for these devices may be poor within some populations, and data loss or technical issues were possible. When there is differential incomplete outcome data by intervention group within trials, these findings are particularly susceptible to bias.
Although this review included only objectively measured physical activity and sedentary time, accelerometers and pedometers are not without limitations. When accelerometers are used to measure physical activity and sedentary time, the accelerometer model, epoch length, non‐wear time, definition of a valid day, wear time criteria, and cut points can differ, causing wide variation between studies and limiting the precision of the effect estimate (as was seen in studies of proportions of participants physically active and sedentary time). For example, a longer epoch length will underestimate MVPA. When studies have minimum wear‐time criteria, the data may be more indicative of habitual physical activity, but sample size will be reduced. The cut points used will also have an impact on physical activity and sedentary time duration (Cain 2013).
Very few of the included studies measured maximal oxygen uptake (VO₂max) directly using gas exchange; this was most often predicted by field tests. This resulted in downgrading of the certainty of evidence for physical fitness due to indirectness. For the most part, studies did use reliable, valid, field‐based measures of aerobic fitness; however the usefulness of these tests is largely determined by participants’ motivation to try their hardest, thus reducing the change that a true measure of fitness was achieved.
Our confidence in the evidence related to both health‐related quality of life and adverse events was limited by potential publication bias, with overall certainty of findings downgraded accordingly. Although many studies reported that no adverse events were reported, most studies did not adequately describe the approach taken to monitor for any adverse events. Although 7 studies reported on health‐related quality of life, others listed these outcomes in protocol papers or in trial registries but did not publish the findings; thus the potential of publication bias remains.
Finally, very few studies reported on the extent to which interventions were implemented as specified. Without adequate process evaluation data, it is not known to what degree students participated in the intervention, and this could have an influence on the impact of the intervention on our outcomes of interest. Information about implementation is important, to understand trial fidelity and for scaling up of interventions in the future. About half of the trials were informed by various theoretical models, including social cognitive theory, socioecological model, self‐determination theory, and the theory of planned behaviour. These theories are intended to promote physical activity at the individual level and may not be as relevant to public health interventions, such as the school‐based studies included in this review (King 2002).
Potential biases in the review process
It is possible that biases were introduced in the review process; however, several steps were taken to minimise this. A comprehensive search strategy, with updates from our previous search strategy to include new terms (such as sedentary time), was used to identify over 9000 citations from 2011 to the present. We did not place limitations by language or publication status. Although efforts were undertaken to minimise this bias (multiple review authors were involved in interpreting results and provided comments on drafts of this update), it is possible that we have interpreted the results to be more positive than they actually are. Readers of this review are cautioned therefore to carefully examine results across studies.
Agreements and disagreements with other studies or reviews
Overall, our findings are similar to those of other systematic reviews and meta‐analyses that have addressed similar questions. A recent systematic review and meta‐analysis examined effects of school‐based physical activity interventions on physical activity and sedentary time, including only cluster‐randomised controlled trials (Love 2019). When studies measured changes in MVPA during the actual intervention period (i.e. during PE class only in an intervention of enhanced PE), there was moderate evidence of effect, whereas when changes in MVPA were examined over the whole school day, effects were inconclusive, and when changes in MVPA were examined across the entire day (both in and out of school time), no effect was seen (Love 2019). It is interesting to note that these study authors also explored the effectiveness of interventions by gender and socioeconomic status and found no difference in effect in terms of either of these variables.
Other reviews have focused more closely on specific intervention types, with similar findings to those presented in this review. A 2019 review of 22 studies that implemented active breaks within the classroom found a small but not significant increase in minutes of MVPA compared to a control group (+3.29 minutes/d, 95% CI ‐0.15 to 8.75) (Masini 2020). However, in this review, only physical activity during class time was included, as opposed to full‐day physical activity measures that were included in this review. Bedard and colleagues found a small reduction in sedentary time when schools took part in an active classroom intervention; however all studies were found to have moderate to high risk of bias (Bedard 2019). A review of active transport interventions found low‐quality evidence to suggest that active transportation can increase transportation‐related MVPA, but with no associated change in physical fitness among children aged 4 to 11 years (Jones 2019).
Trial flow diagram.
Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included trials (blank cells indicate that the particular outcome was not measured in some trials).
Risk of bias summary: review authors' judgements about each risk of bias item for each included trial (blank cells indicate that the particular outcome was not measured in some trials).
Funnel plot of comparison: 1.2 Physical activity duration: meta‐analysis.
Funnel plot of comparison: 1.5 Sedentary time: meta‐analysis.
Funnel plot of comparison: 1.8 Physical fitness: meta‐analysis.
![Funnel plot of comparison: 1.11 BMI: meta‐analysis [z‐scores].](/es/cdsr/doi/10.1002/14651858.CD007651.pub3/media/CDSR/CD007651/image_n/nCD007651-FIG-07.svg)
Funnel plot of comparison: 1.11 BMI: meta‐analysis [z‐scores].
![Funnel plot of comparison: 1.13 BMI: meta‐analysis [kg/m2].](/es/cdsr/doi/10.1002/14651858.CD007651.pub3/media/CDSR/CD007651/image_n/nCD007651-FIG-08.svg)
Funnel plot of comparison: 1.13 BMI: meta‐analysis [kg/m2].
| Physical activity participation: all data | ||||||
| Study | Study population | Intervention group | Control Group | Measurement period | Overall effect | Comment |
|---|---|---|---|---|---|---|
| Children: before and after school programme | ||||||
| Jago 2015 | Year 7 female students | After‐school dance classes | Provided data only | 20 weeks | Between group difference in % meeting 60 min/day of MVPA: −1.11% (95% CI −1.68, −0.73) | |
| 1 year | Between group difference in % meeting 60 min/day of MVPA: −1.18% ( (95% CI −1.82, 0.76) | |||||
| Children: schooltime PA | ||||||
| Kobel 2014 | Pupils at primary school, grades 1 and 2 | Teacher training, PA education, and active breaks | No intervention | 1 year | Between‐group difference in % meeting 60 min/day of MVPA: 10.4% (not statistically significant) Intervention group: 54.7% Control group: 44.3% | |
| Children: multi‐component interventions | ||||||
| Adab 2018 | Year 1 students (aged 5 to 6 years) | 30 min of additional MVPA on each school day, cooking workshops, a 6‐week healthy eating program, and information sheets for families | Ongoing year 2 health related activities and education resources, excluding topics related to healthy eating and PA | 15 months | Between‐group difference in % meeting 60 min/day of MVPA: 0.005% (95% CI −0.101, 0.140) | |
| 18 months | Between‐group difference in % meeting 60 min/day of MVPA: −0.067% (95% CI −0.165, 0.096) | |||||
| Adolescents: multi‐component interventions | ||||||
| Andrade 2014 | Grades 8 and 9 students | ACTIVITAL individual‐ and environmental‐based intervention | Standard curriculum | 28 months | Between‐group difference in % meeting guidelines: 12.22% (P < 0.01) Intervention group: ‐5.87% Control: ‐18.09% | |
| Harrington 2018 | Female students in years 7 to 9, 11 to 14 years old | Support for PA, PE, and school sport culture and practices with the support of the Youth Sport Trust and a hub school | Continued with normal PA habits | 7 months (midpoint) | Meeting guidelines: OR: 0.78 (0.23, 2.65) | |
| 14 months | Meeting guidelines: OR: 0.65 (0.23, 1.85) | |||||
Comparison 1: PA programme vs no PA programme, Outcome 1: Physical activity participation: all data
Comparison 1: PA programme vs no PA programme, Outcome 2: Physical activity duration (minutes/d): meta‐analysis
Comparison 1: PA programme vs no PA programme, Outcome 3: Physical activity duration by intervention type (minutes/d): meta‐analysis
| Physical activity duration: additional data | ||||||
| Study | Study population | Intervention group | Control Group | Measurement period | Overall effect | Comment |
|---|---|---|---|---|---|---|
| Before and after school programmes | ||||||
| Zhou 2019 | Junior high school students, grade 7 | I1: Biweekly after school program | Regular PE (2 days per week) | 32 weeks | % of time spent in MVPA: MD 1.99 (95% CI: 1.68, 2.30) I1: m 4.22 (sd 1.39) Control: m 2.23 (sd 1.52)
| % time reported, not min/day |
| I2: Enhanced PE (3 days per week) plus after school program | Regular PE (2 days per week) | 32 weeks | % of time spent in MVPA: MD 4.98 (95% CI: 4.62, 5.34) I2: m 7.21 (sd 1.84) Control: m 2.23 (sd 1.52) | Authors note that statistically significant changes were found from baseline to follow‐up in both intervention groups but not the control group however analyses were not described. | ||
| Enhanced PE | ||||||
| Ten Hoor 2018 | Secondary school students, 11 to 15 years old | Strength training and motivational interviewing | Usual curriculum | 1 year | Between group difference in % of time spent in MPVA tested, P = 0.046 | No values reported |
| Zhou 2019 | Junior high school students, grade 7 | I1: Enhanced PE (3 days per week) | Regular PE (2 days per week) | 32 weeks | % of time spent in MVPA: MD 3.12 (95% CI: 2.76, 3.48) I1: m 5.35 (sd 1.79) Control: m 2.23 (sd 1.52) | % time reported, not min/day |
| I2: Enhanced PE (3 days per week) plus after school program | % of time spent in MVPA: MD 4.98 (95% CI: 4.62, 5.34) I2: m 7.21 (sd 1.84) Control: m 2.23 (sd 1.52) | Authors note that statistically significant changes were found from baseline to follow‐up in both intervention groups but not the control group however analyses were not described. | ||||
| Multi‐component intervention | ||||||
| Corepal 2019 | Students age 12‐14 | Pedometer challenge | Usual school | Baseline | Intervention: m 33.3 min/day, IQR: 23.6, 49.0) | Feasibility trial, therefore statistical testing not conducted |
| 22 weeks | MD: ‐14.4 min/day Intervention: m 33.0 min/day, IQR: 20.0, 46.2 Control: m 47.4 min/day, IQR: 32.7, 65.1 | No estimates of variance given, only mean and interquartile range | ||||
| Salmon 2008 | Grade 5 students (10 to 11 years old) | I1: Behavioral modification group, I2: fundamental motor skills group, I3: combined behavioral modification and fundamental motor skills group | Usual classroom lessons | 1 school year | Adjusted between group difference (vs. control group) I1: MD 2.8 (95% CI 0.3, 5.4) min/day I2: MD 7.8 (95% CI 3.4, 12.3) min/day I3: MD 3.1 (95% CI ‐0.58, 6.7) min/day | Vigorous PA only |
| 1 year post‐intervention | Adjusted between group difference (vs. control group) I1: MD 2.8 (95% CI 0.2, 5.4) min/day I2: MD 7.7 (95% CI 3.2, 12.2) min/day I3: MD 3.0 (95% CI ‐0.59, 6.6) min/day | Vigorous PA only | ||||
| Schooltime PA | ||||||
| Ford 2013 | Primary school students aged 5 to 11 years | Accumulated brisk walking program | Normal school lessons | 15 weeks | Change from baseline MD ‐27.4 (95% CI: ‐91.0, 36.2) counts per min Intervention group: ‐29.2 (‐72.0, 13.6) counts per min, P = 0.415 | Weekday counts per min only |
| Magnusson 2011 | Children attending grade 2 (born in 1999) | Students engaged in PA during PE lessons, recess, and during classes; schools had access to PA equipment to use in school lessons; teaching materials promoting PA were provided | Followed the general PA curriculum | 1 year (midpoint) | Group x time interaction in multivariable model P < 0.0001 | |
| 2 years | Group x time interaction in multivariable model P = 0.10 | |||||
Comparison 1: PA programme vs no PA programme, Outcome 4: Physical activity duration: additional data
Comparison 1: PA programme vs no PA programme, Outcome 5: Sedentary time (minutes/d): meta‐analysis
Comparison 1: PA programme vs no PA programme, Outcome 6: Sedentary time (minutes/d) by intervention type: meta‐analysis
| Sedentary time: additional data | ||||||
| Study | Study population | Intervention group | Control Group | Measurement period | Overall effect | Comment |
|---|---|---|---|---|---|---|
| Before and after school programmes | ||||||
| Zhou 2019 | Junior high school students, grade 7 | I1: Biweekly after school program | Regular PE (2 days per week) | 32 weeks | % of time spent sedentary: MD 1.34 (95% CI: ‐0.73, 3.41) I1: m 75.74 (sd 8.81) Control: m 74.40 (sd 10.80) | % time reported, not min/day |
| I2: Enhanced PE (3 days per week) plus after school program | Regular PE (2 days per week) | 32 weeks | % of time spent sedentary: MD 0.11 (95% CI: ‐2.31, 2.54) I2: m 74.51 (sd 11.95) Control: m 74.40 (sd 10.80) | Authors note that statistically significant changes were found from baseline to follow‐up in the after school program only, however analyses were not described or presented | ||
| Enhanced PE | ||||||
| Lonsdale 2019a | Grade 8 students | Teacher PE training | Standard teaching | 7‐8 months | % time spent sedentary: MD 0.92 (95% CI −0.28, 2.13) | % time reported, not min/day |
| 14‐15 months | % time spent sedentary: MD 0.02 (95% CI −0.99, 0.95) | |||||
| Ten Hoor 2018 | Secondary school students, 11 to 15 years old | Strength training and motivational interviewing | Usual curriculum | 1 year | Between group difference in % of time spent sedentary, P = 0.715 | % time reported, not min/day |
| Zhou 2019 | Junior high school students, grade 7 | I1: Enhanced PE (3 days per week) | Regular PE (2 days per week) | 32 weeks | % of time spent sedentary: MD 1.11 (95%CI: ‐1.09, 3.31) I1: m 75.51 (sd 9.64) Control: m 74.40 (sd 10.80) | % time reported, not min/day |
| I2: Enhanced PE (3 days per week) plus after school program | Regular PE (2 days per week) | 32 weeks | % of time spent sedentary: MD 0.11 (95% CI: ‐2.31, 2.54) I2: m 74.51 (sd 11.95) Control: m 74.40 (sd 10.80) | Authors note that statistically significant changes were found from baseline to follow‐up in the after school program only group, however analyses were not described. | ||
| Multi‐component intervention | ||||||
| Corepal 2019 | Students 12‐14 years old | Pedometer challenge | Usual school | Baseline | Intervention: m 449.6 min/day, IQR: 416.5, 524.3 Control: m 466.3 min/day, IQR: 410.0, 534.9 | Feasibility trial therefore no statistical analyses performed |
| 22 weeks | MD 1.2 min/day Intervention: m 454.7 min/day, IQR: 405.7, 517.8 Control: m 453.5 min/day IQR: 399.8, 529.6 | Variance cannot be calculated as only mean and interquartile range reported | ||||
Comparison 1: PA programme vs no PA programme, Outcome 7: Sedentary time: additional data
Comparison 1: PA programme vs no PA programme, Outcome 8: Physical fitness (mL/kg/min): meta‐analysis
Comparison 1: PA programme vs no PA programme, Outcome 9: Physical fitness (mL/kg/min) by intervention type: meta‐analysis
| Physical fitness: additional data | ||||||
| Study | Study population | Intervention group | Control Group | Measurement period | Overall effect | Comment |
|---|---|---|---|---|---|---|
| Before or after school programme | ||||||
| Carlin 2018 | Female students, aged 11 to 13 years old | Brisk walking intervention | Continued with normal PA habits | 12 weeks | No significant changes were observed between group | Data not shown |
| 6 months | No significant changes were observed between group | |||||
| de Heer 2011 | Children in grades 3 to 5 with no condition that would endanger their own or others’ safety | Bienstar intervention of health education and 45 min to 60 min of after school PA | Grade 4 health workbooks and incentives | 12 weeks | Shuttle run performance: MD 3.87 (SE 1.51) laps, P = 0.012 | |
| Wang 2008 | Grade 3 students | 'FitKid' after‐school intervention sessions | — | 3 years | Heart rate response to step test, group*time interaction P < 0.01 | |
| Zhou 2019 | Junior high school students, grade 7 | I1: Biweekly after school program | Regular PE (2 days per week) | 32 weeks | 20‐m shuttle run performance (change from baseline): MD 8.86, 95% CI: 5.68, 12.04) I1: m 12.38 (95% CI 10.2, 14.56) Control: m 3.52 (95% CI 1.18, 5.85) | Authors note that statistically significant changes were found between both intervention and control groups but analyses were not described |
| I2: Enhanced PE (3 days per week) plus after school program | Regular PE (2 days per week) | 32 weeks | 20‐m shuttle run performance (change from baseline): MD 22.26 laps (95% CI: 19.15, 25.37) I2: m 25.78 (95% CI: 23,7, 27.86) Control: m 3.52 (95% CI: 1.18, 5.85) | |||
| Enhanced PE | ||||||
| Ketelhut 2020 | Grade 3 students | High intensity interval training | Regular PE | 12 weeks | Between‐group difference in aerobic fitness z‐score: 7.7 (95% CI 2.3, 13.2) | |
| Kriemler 2010 | Grades 1 and 5 students | 2 additional 45‐minute PE lessons/week, activity breaks, and PA homework | Usual, mandatory PE lessons | 9 months | Adjusted shuttle run performance: MD −0.12 (95% CI −0.21, −0.03) stages, P = 0.009 | |
| Ordóñez Dios 2019 | Children age 11‐12 years | Daily run added to regular PE | Regular PE | 12 weeks | 1km time Between‐group difference in change from baseline: ‐0.55 minutes, 95% CI: ‐0.75, ‐0.35 | |
| Thivel 2011 | Children in grades 1 or 2 | 120 min of additional supervised PE | Habitual 2 H of PE/week | 6 months | Shuttle run performance Between‐group difference in change from baseline: m 0.36, 95% CI: 0.23, 0.49 stages | |
| Zhou 2019 | Junior high school students, grade 7 | I1: Enhanced PE (3 days per week) | Regular PE (2 days per week) | 32 weeks | 20‐m shuttle run performance (change from baseline): MD 14.33 laps (95%CI: 11.16, 17.50) I1: m 17.85 (95% CI 15.68, 20.02) Control: m 3.52 (95% CI 1.18, 5.85) | Authors note that statistically significant changes were found between both intervention and control groups but analyses were not described |
| I2: Enhanced PE (3 days per week) plus after school program | 20‐m shuttle run performance (change from baseline): MD 22.26 laps (95% CI: 19.15, 25.37) I2: m 25.78 (95% CI: 23,7, 27.86) Control: m 3.52 (95% CI: 1.18, 5.85) | |||||
| Multi‐component intervention | ||||||
| Aburto 2011 | Students in grades 4 and 5 | I1: basic intervention of environmental and policy‐level change I2: plus intervention adding additional resources and daily morning exercise | No change to the standard practices | 18 months | From baseline to follow‐up, there were no significant changes in either group in distance run during the 9 minute run test (P > 0.05) | |
| Andrade 2014 | Grades 8 and 9 students | ACTIVITAL individual‐ and environmental‐based intervention | Standard curriculum | 28 months | Shuttle run performance: MD −0.19 (95% CI −0.54, 0.16) min | |
| Burke 1998 | — | I1: standard PA and nutrition program including classroom lessons, fitness sessions daily, and nutrition program, I2: I1 plus a PA enrichment program for higher‐risk children | No program | 9 months | Shuttle run performance Girls: Number of laps increased in both intervention groups vs. control group (P = 0.0001) Boys: Number of laps increased in both intervention groups vs. control group (P = 0.0008) | |
| Cohen 2015 | Grades 3 and 4 students | Teacher learning, PA policies, school‐community linkages | Usual PE and school sport programs | 12 months | Shuttle run performance: MD 5.4 (95% CI 2.3, 8.6) laps, P = 0.003 | 20 m shuttle run test |
| Jago 2011 | Students enrolled in grade 6 | Education, social marketing, food environment, PE curriculum, and equipment provision | Recruitment and data collection only | 2.5 years | Between‐group difference in change in shuttle run performance: MD 0.2 laps, 95% CI: ‐0.5, 0.9) | |
| Jansen 2011 | Grades 3 to 5 | 3 PE sessions/week, additional after school sport and play, classroom education, and parent health promotion | Continued with usual curriculum | 1 school year | Shuttle run performance: MD 0.57 (95% CI 0.13, 1.01) laps | |
| Grades 6 to 8 | Shuttle run performance: MD 0.04 (95% CI ‐0.45, 0.53) laps | |||||
| Madsen 2015 | Grades 3, 4, and 5 students | Nutrition education curriculum, Playworks structured recess before or after school activities, PA and games implemented by teachers | — | 2 years | Mile run time: MD 0.2 (95% CI ‐0.8, 0.4) minutes | |
| Reed 2008 | Grades 4 and 5 children | Action Schools!BC whole‐school PA approach | Regular program of PE and school‐based PA | 11 months | Shuttle run performance, adjusted for baseline values: MD 6 laps, 95% CI: 1.6, 10.4 | |
| Seibert 2019 | Grade 5, 9 to 10 years old | Physically active lessons (45 min) 2‐3d/week on days without PE, physically active homework and physically active recess | Normal routine, 135 min/week of PA | 10 months | Progressive Aerobic Cardiovascular Endurance Run score (change from baseline): MD ‐1.1, 95% CI: ‐2.2, 0.01) Fitness z‐scores (change from baseline: MD ‐0.10, 95% CI: ‐0.15, ‐0.04 | Change favours the control group |
| Toftager 2014 | — | Physical and organizational environmental changes | — | 2 years | Shuttle run distance: MD 6 (95% CI ‐20, 31) metres, P = 0.43 | |
| Trevino 2004 | All grade 4 children | Health programming regarding 3 health behavior messages associated with diabetes mellitus control and goal setting | — | 7 months | Fitness score: MD 1.87 (95% CI ‐1.44, 5.17) points, P = 0.04 | Harvard Step Test used |
| Schooltime PA | ||||||
| Breheny 2020 | Years 3 (aged 7–8 years) and 5 (aged 9–10 years) | Daily mile, 15‐minutes of PA incorporated into the school day | Usual school day | 12 months | Linear track test: MD ‐37.4 (95% CI ‐74.7, ‐0.19) metres | Difference favours control group |
| de Greeff 2016 | Grades 2 and 3 students | Physically active mathematics and language lessons | Usual curriculum | 2 years | Shuttle run performance: MD adjusted for baseline values 0.05 stages, SE: 0.14 | |
| Donnelly 2017 | Grades 2 and 3 students | Academic Achievement and Physical Activity Across the Curriculum lessons, 160 min/week of MVPA | Traditional classroom instruction and typical PE schedule | 3 years | Progressve Aerobic Cardiorespiratory Endurance Run test performance: MD 1.3 laps, 95% CI: ‐0.5, 3.1 | |
| Have 2018 | Grade 1 students | Active math lessons | Regular classroom instruction | 10 months | Between group difference in intermittent shuttle run test performance: MD 10.0 (SE 13.9) metres, P > 0.05 | |
| Leahy 2019 | Grade 11 students | Burn2Learn, multi component high intensity interval training | Usual school activities | 14 weeks | Shuttle run performance: MD 8.9 (95% CI 1.7, 16.2) laps, P = 0.01 | |
| Magnusson 2011 | Children attending grade 2 | Students engaged in PA during PE lessons, recess, and during classes; schools had access to PA equipment to use in school lessons; teaching materials promoting PA were provided | Followed the general PA curriculum | 2 years | Load achieved on a cycling test: MD 0.37 (95% CI ‐0.27, 1.01) w/kg, P = 0.18 | |
| Resaland 2016 | Grade 5 and 6 | Physically active Norwegian, mathematics, and English lessons on the playground; PA breaks and PA homework | Curriculum‐prescribed PE and PA | 7 months | Intermittent shuttle run test performance: MD 6.9 (95% CI −8.9, 22.6) metres, P = 0.387 | |
| Seljebotn 2019 | Grade 5 students | Physically active lessons, active homework, and physically active recess | Continued normal routine, approximately 135 min/week of PA | 10 months | No significant differences found (no data reported) | |
| Tarp 2016 | Grades 6 and 7 students | 60 min of PA during school time, PA homework | Normal practice | 20 weeks | Shuttle run test performance: MD 9.4 (95% CI ‐3.7, 22.4) metres, P = 0.16 | |
| Torbeyns 2017 | Grades 3 and 4 students | Cycling desks | No lifestyle change | 22 weeks | Shuttle run test performance (change from baseline): MD 0.5 stages, 95% CI: ‐0.5, 1.5 | |
Comparison 1: PA programme vs no PA programme, Outcome 10: Physical fitness: additional data
![Comparison 1: PA programme vs no PA programme, Outcome 11: BMI: meta‐analysis [z‐scores]](/es/cdsr/doi/10.1002/14651858.CD007651.pub3/media/CDSR/CD007651/image_n/nCD007651-CMP-001.11.svg)
Comparison 1: PA programme vs no PA programme, Outcome 11: BMI: meta‐analysis [z‐scores]
![Comparison 1: PA programme vs no PA programme, Outcome 12: BMI by intervention type: meta‐analysis [z‐scores]](/es/cdsr/doi/10.1002/14651858.CD007651.pub3/media/CDSR/CD007651/image_n/nCD007651-CMP-001.12.svg)
Comparison 1: PA programme vs no PA programme, Outcome 12: BMI by intervention type: meta‐analysis [z‐scores]
![Comparison 1: PA programme vs no PA programme, Outcome 13: BMI: meta‐analysis [kg/m2]](/es/cdsr/doi/10.1002/14651858.CD007651.pub3/media/CDSR/CD007651/image_n/nCD007651-CMP-001.13.svg)
Comparison 1: PA programme vs no PA programme, Outcome 13: BMI: meta‐analysis [kg/m2]
![Comparison 1: PA programme vs no PA programme, Outcome 14: BMI by intervention type: meta‐analysis [kg/m2]](/es/cdsr/doi/10.1002/14651858.CD007651.pub3/media/CDSR/CD007651/image_n/nCD007651-CMP-001.14.svg)
Comparison 1: PA programme vs no PA programme, Outcome 14: BMI by intervention type: meta‐analysis [kg/m2]
| BMI: additional data | ||||||
| Study | Study population | Intervention group | Control Group | Measurement period | Overall effect | Comment |
|---|---|---|---|---|---|---|
| Before or after school programme | ||||||
| Carlin 2018 | Female students, aged 11 to 13 years old | Brisk walking intervention | Continued with normal PA habits | 12 weeks | No between group differences | BMI values not reported |
| 6 months | No between group differences | |||||
| Enhanced PE | ||||||
| Ardoy 2011 | Students age 12 to 14, enrolled in first year of secondary school | I1: 4 sessions/week of PE I2: 4 sessions/week of PE with emphasis on increasing intensity | 2 sessions/week of PE | 16 weeks | No between group differences | BMI values not reported |
| Multi‐component intervention | ||||||
| Burke 1998 | — | I1: standard PA and nutrition program including classroom lessons, fitness sessions daily, and nutrition program I2: I1 plus a PA enrichment program for higher‐risk children | No program | 9 months | Significant difference between I1 and control group in boys only, P = 0.016 No significant difference between I1 and control in girls, or I2 and control | No BMI values reported |
| 15 months | No significant differences between groups for boys or girls | |||||
| Ickovics 2019 | Grades 5 and 6 students | I1: PA school wellness policy I2: PA + nutrition school wellness policy | C1: Nutrition school wellness policy C2: delayed control | 3 years | No significant group by time interaction P = 0.94 | No BMI values reported |
| Salmon 2008 | Grade 5 students (approximately 10 to 11 years old) | I1: behavioral modification group I2: fundamental motor skills group I3: combined behavioral modification and fundamental motor skills group | Usual classroom lessons | 1 school year | Adjusted BMI/sex‐age population median I1: MD ‐0.40 (95% CI ‐1.11, 0.30) kg/m2 I2: MD ‐0.50 (95% CI ‐1.25, 0.25) kg/m2 I3: MD ‐1.30 (95% CI ‐2.29, ‐0.31) kg/m2 | BMI/sex‐age population median not kg/m2 or z‐score |
| Suchert 2015 | Students age 12 to 17 years | Multilevel intervention targeting students, classrooms, schools, and parents | No intervention | 12 weeks | — | BMI percentile, not kg/m2 or z‐score |
| 1 year | BMI percentile: MD 1.09 (95% CI −0.64, 2.82), P = 0.215 | |||||
| Schooltime PA | ||||||
| Donnelly 2017 | Grades 2 and 3 students | Academic Achievement and Physical Activity Across the Curriculum lessons, 160 min/week of MVPA | Traditional classroom instruction and typical PE schedule | 3 years | BMI percentile (change from baseline): MD ‐2.3, 95% CI: ‐4.8, 0.2 | BMI percentile, not kg/m2 or z‐score |
| Kobel 2014 | Pupils at primary school, grades 1 and 2 | Teacher training, PA education, and active breaks | No intervention | 1 year | Adjusted BMI percentile (change from baseline): MD 0.5, 95% CI: ‐0.5, 1.5 | BMI percentile, not kg/m2 or z‐score |
| Williamson 2007 | Students in grades 2 to 6 | Healthy Eating and Exercise program to increase PA during the school day and at home | Alcohol/Drug/Tobacco abuse prevention program | 2 years | No between group differences, P = 0.5458 | BMI values not reported |
Comparison 1: PA programme vs no PA programme, Outcome 15: BMI: additional data
| Health‐related quality of life: all data | ||||||
| Study | Study population | Intervention group | Control Group | Measurement period | Overall effect | Comment |
|---|---|---|---|---|---|---|
| Children | ||||||
| Adab 2018 | Year 1 students (aged 5 to 6 years) | 30 min of additional MVPA on each school day, cooking workshops, a 6‐week healthy eating program, and information sheets for families | Ongoing year 2 health related activities and education resources, excluding topics related to healthy eating and PA | 15 months
30 months | MD −0.630 (95% CI −4.385, 3.124) points
MD 1.248 (95% CI −2.301, 4.796) points | Measured using Pediatric quality of life inventory |
| Breheny 2020 | Year 3 (aged 7‐8 years) and 5 (9‐10 years) students | Daily Mile, 15 minutes of running/walking within the school grounds during the school day, not to replace PE | Usual school | 12 months | MD 0.010 (95% CI ‐0.002, 0.04) | Measured using Child Health Utility 9D |
| Jago 2015 | Year 7 female students | After‐school dance classes | Provided data only | Baseline T1 T2 | Baseline MD 0.01 points, P = 0.309 T1 MD 0.0 points, P = 0.667 T2 MD 0.0 points, P = 0.382 | Meausured using European Quality of Life‐5 Dimensions Youth survey |
| Jago 2019 | Year 3 and 4 students, 7 to 9 years old | Action 3:30R after school PA club | — | End of study | No difference in utility scores or z‐scores between groups | Measured using KIDSCREEN‐10 |
| Resaland 2016 | Grade 5 and 6 | Physically active Norwegian, mathematics, and English lessons on the playground; PA breaks and PA homework | Curriculum‐prescribed PE and PA | End of study | No significant differences found (no data shown) | Measured using KIDSCREEN‐10 |
| Adolescents | ||||||
| Harrington 2018 | Female students in years 7 to 9, 11 to 14 years old | Support for PA, PE, and school sport culture and practices with the support of the Youth Sport Trust and a hub school | Continued with normal PA habits | End of study | No significant differences found (no data shown) | Measured using Child Health Utility 9D |
| Leahy 2019 | Grade 11 students | Burn2Learn, multi component high intensity interval training | Usual school activities | 14 weeks | MD −2.1 (95% CI −4.0, −0.3) points, P = 0.02 | Measured using Strengths and Difficultlies Questionnaire; lower score indicates fewer perceived difficulties |
Comparison 1: PA programme vs no PA programme, Outcome 16: Health‐related quality of life: all data
| Adverse events: all data | ||
| Study | Participants with at least one adverse event | Participants discontinuing trial due to an adverse event |
|---|---|---|
| Andrade 2014 | 0 | 0 |
| Breheny 2020 | 0 | 0 |
| Cohen 2015 | 0 | 0 |
| Ford 2013 | 0 | 0 |
| Harrington 2018 | 0 | 0 |
| Ickovics 2019 | 0 | 0 |
| Jago 2011 | Baseline: 205 events End of Study: 141 events | 0 |
| Jago 2015 | 0 | 0 |
| Ketelhut 2020 | 0 | 0 |
| Leahy 2019 | 0 | 0 |
| Martinez‐Vizcaino 2014 | 0 | 0 |
| Müller 2019 | 0 | 0 |
| Nogueira 2014 | 1 | 0 |
| Okely 2011 | 0 | 0 |
| Salmon 2008 | 0 | 0 |
| Wang 2008 | Year 1: 24 events | 0 |
Comparison 1: PA programme vs no PA programme, Outcome 17: Adverse events: all data
| School‐based physical activity programmes for promoting physical activity and fitness in children and adolescents aged 6 to 18 years | ||||
| Population: children and adolescents aged 6 to 18 years Settings: primarily within the school setting Intervention: educational, health promotion, counselling, and management strategies focused on promotion of physical activity and fitness Comparison: standard, currently existing physical education programmes in schools | ||||
| Outcomes | Anticipated effects (95% CI) | No. of participants | Certainty of the evidence | |
|---|---|---|---|---|
| Risk with control | Risk with intervention | |||
| % of participants physically active [follow‐up: 12 weeks to 12 months] | % physically active ranged from 2% to 50% | % physically active ranged from 1.11% lower to 12.22% higher. | 6,068 (5) | ⊕⊝⊝⊝ very lowa |
| Moderate to vigorous physical activity (minutes/d) [follow‐up: 12 weeks to 3 years] | ‐3.63 (‐5.03 to ‐2.23) | MD 0.73, 95% CI 0.16 to 1.30 | 20,614 (33) | ⊕⊕⊕⊝ moderateb |
| Sedentary time (minutes/d) | 27.77 (‐21.34 to 76.88) | MD ‐3.78, 95% CI ‐7.80 to 0.24 | 11,914 (16) | ⊕⊕⊝⊝ lowc |
| Physical fitness (VO₂ max, mL/kg/min) | ‐1.00 (‐1.59 to ‐0.41) | MD 1.19, 95% CI 0.57 to 1.82 | 3,980 (13) | ⊕⊕⊝⊝ lowd |
| BMI (z‐score) | ‐0.01 (‐0.08 to 0.06) | MD ‐0.06, 95% CI ‐0.09 to ‐0.02 | 22,948 (21) | ⊕⊕⊝⊝ lowe |
| BMI (kg/m²) | ‐0.35 (‐1.06 to 0.36) | MD ‐0.07, 95% CI ‐0.15 to 0.01 | 34,337 (50) | |
| Health‐related quality of life [follow‐up: 15 weeks to 12 months] | Not estimable; insufficient data reported within studies | 4,687 (7) | ⊕⊝⊝⊝ very lowf | |
| Adverse events [follow‐up: 12 weeks to 3 years] | Not estimable; only 3 studies reported any adverse events | 11,698 (16) | ⊕⊝⊝⊝ very lowg | |
| BMI: body mass index; CI: confidence interval; MD: mean difference; min/d: minutes per day; VO₂max: maximal oxygen uptake. | ||||
| GRADE Working Group grades of evidence. | ||||
| aDowngraded by one level each for inconsistency (large variation in effects across studies), imprecision (wide confidence intervals), and risk of bias (high or unclear in most studies). bDowngraded by one level for inconsistency (visual inspection of forest plots and I² value from meta‐analysis). cDowngraded by one level for imprecision of results (wide confidence intervals) and risk of bias (high or unclear in many studies). dDowngraded by one level for inconsistency (visual inspection of forest plots and I² value from meta‐analysis) and indirectness (estimated vs measured VO₂ peak). eDowngraded by one level for inconsistency (visual inspection of forest plots and I² value from meta‐analysis), risk of bias (high or unclear in most studies). fDowngraded by one level for inconsistency (large variation across studies), risk of bias (high or unclear in most studies), publication bias (most studies not reporting on health‐related quality of life or describing full results). gDowngraded by one level for inconsistency (large variation across studies), publication bias (most studies not reporting on adverse events or methods for monitoring), risk of bias (high or unclear in most studies). | ||||
| Trial ID (design) | Interventions and comparators | Screened/eligible | Randomised | Finishing trial | Randomised finishing trial |
|---|---|---|---|---|---|
| I: Daily Mile | —/— | 1153 | 1107 | 96.0 | |
| C: usual school routine | 1127 | 1070 | 94.9 | ||
| total: | 2280 | 2177 | 95.5 | ||
| I: high‐intensity interval training during PE | —/— | — | 22 | — | |
| C: usual PE | 24 | ||||
| total: | — | 46 | |||
| — | |||||
| Belton 2019 (cluster‐RCT) | I: multi‐component PE, whole‐school and parent‐targeted intervention | 564/534 | 275 | 123 | 44.7 |
| C: usual care | 259 | 126 | 48.6 | ||
| total: | 534 | 249 | 46.6 | ||
| Corepal 2019 | I: pedometer challenge | —/— | 142 | 136 | 95.8 |
| C: usual school | 82 | 81 | 98.8 | ||
| total: | 224 | 217 | 96.9 | ||
| Ickovics 2019 (cluster‐RCT) | I1: PA school wellness policy | —/756 | 413 | 330 | 79.9 |
| I2: PA + nutrition school wellness policy | |||||
| C1: nutrition school wellness policy | 305 | 265 | 86.9 | ||
| C2: delayed control | |||||
| total: | 718 | 595 | 82.9 | ||
| Jago 2019 (cluster‐RCT) | I: Action 3:30R after‐school PA club | 1139/1125 | 170 | 113 | 66.5 |
| C: — | 165 | 139 | 84.2 | ||
| total: | 335 | 252 | 75.2 | ||
| Leahy 2019 (cluster‐RCT) | I: Burn2Learn, multi‐component high‐intensity interval training | —/68 | 38 | 32 | 84.2 |
| C: usual school activities | 30 | 29 | 96.7 | ||
| total: | 68 | 61 | 89.7 | ||
| Lonsdale 2019a | I: teacher PE training | —/1806 | 693 | 630 | 90.9 |
| C: standard teaching | 728 | 628 | 86.3 | ||
| total: | 1421 | 1258 | 88.5 | ||
| Müller 2019 | I1: PA only | 1009/944 | — | 265 | — |
| I2: PA + health education | |||||
| I3: PA + health education + nutrition | |||||
| C1: health education + nutrition | — | 398 | — | ||
| C2: no PA | |||||
| total: | 944 | 663 | 70.2 | ||
| I: 2 x 45‐minute PE sessions per week and daily run | —/— | — | 45 | — | |
| C: 2 x 45‐minute PE sessions per week | — | 44 | — | ||
| total: | — | 89 | — | ||
| I: 4 core strategies to increase PA | —/— | 2495 | — | — | |
| C: usual PE | 2399 | — | — | ||
| total: | 4894 | — | — | ||
| Seljebotn 2019 | I: physically active lessons, active homework, physically active recess | —/473 | 228 | 224 | 98.2 |
| C: continued normal routine, approximately 135 minutes/week of PA | 219 | 218 | 99.5 | ||
| total: | 447 | 442 | 98.9 | ||
| Zhou 2019 | I1: modified PE | —/— | 204 | 163 | 79.9 |
| I2: after school PA programme | 200 | 180 | 90.0 | ||
| I3: modified PE and after school PA programme | 178 | 168 | 94.4 | ||
| C: regular PE | 176 | 170 | 96.6 | ||
| total: | 758 | 681 | 89.8 | ||
| Adab 2018 | I: 30 minutes of additional MVPA on each school day, cooking workshops, a 6‐week healthy eating programme, information sheets for families | —/— | 1134 | 660 | 58.2 |
| C: ongoing Year 2 health‐related activities and education resources, excluding topics related to healthy eating and PA | 1328 | 732 | 55.1 | ||
|
| total: | 2462 | 1392 | 56.5 | |
| Carlin 2018 | I: brisk walking intervention | —/— | 101 | 100 | 99.0 |
| C: continued with normal PA habits | 98 | 97 | 99.0 | ||
| total: | 199 | 197 | 99.0 | ||
| Harrington 2018 | I: support for PA, PE, and school sport culture and practices with support of the Youth Sport Trust and a hub school | —/1753 | 867 | 735 | 84.8 |
| C: usual practice of PE and sport | 885 | 626 | 70.7 | ||
| total: | 1752 | 1361 | 77.7 | ||
| Have 2018 | I: active math lessons | —/557 | 294 | 268 | 91.2 |
| C: regular classroom instruction | 211 | 182 | 86.3 | ||
| total: | 505 | 450 | 89.1 | ||
| Pablos 2018 | I: lunchtime extracurricular PA | —/210 | 100 | 82 | 82.0 |
| C: continued with daily activities | 90 | 76 | 84.4 | ||
| total: | 190 | 158 | 83.2 | ||
| Robbins 2018 | I: an after school PA club, counselling, interactive Internet‐based sessions | 4192/1543 | 766 | 706 | 92.2 |
| C: no additional after school programming | 777 | 680 | 87.5 | ||
| total: | 1543 | 1386 | 89.8 | ||
| Siegrist 2018 | I: weekly lifestyle lessons | 792/— | 331 | 243 | 73.4 |
| C: usual activities | 257 | 191 | 74.3 | ||
| total: | 588 | 434 | 73.8 | ||
| Ten Hoor 2018 | I: strength training and motivational interviewing | —/808 | 353 | 262 | 74.2 |
| C: usual curriculum | 342 | 246 | 71.9 | ||
| total: | 695 | 508 | 73.1 | ||
| Donnelly 2017 | I: Academic Achievement and Physical Activity Across the Curriculum lessons, 160 minutes/week of MVPA | —/698 | 316 | 244 | 77.2 |
| C: traditional classroom instruction and typical PE schedule | 268 | 204 | 76.1 | ||
| total: | 584 | 448 | 76.7 | ||
| Farmer 2017 | I: school‐specific playground action plan | —/— | 812 | 344 | 42.4 |
| C: no change to school play spaces | 851 | 325 | 38.2 | ||
| total: | 1663 | 669 | 40.2 | ||
| Sutherland 2017 | I: modified Supporting Children's Outcomes using Rewards, Exercise and Skills programme | —/1959 | 571 | — | — |
| C: delivered school PA practices according to the curriculum | 568 | — | — | ||
| total: | 1139 | — | — | ||
| Torbeyns 2017 (RCT) | I: cycling desks | —/— | 28 | 21 | 75.0 |
| C: no lifestyle change | 28 | 23 | 82.1 | ||
| total: | 56 | 44 | 78.6 | ||
| Daly 2016 | I: specialist‐taught PE intervention | —/— | 457 | 273 | 59.7 |
| C: usual PE programme | 396 | 267 | 67.4 | ||
| total: | 853 | 540 | 63.3 | ||
| de Greeff 2016 | I: physically active mathematics and language lessons | —/— | — | 181 | — |
| C: usual curriculum | — | 195 | — | ||
| total: | 388 | 376 | 96.9 | ||
| Drummy 2016 | I: teacher‐led activity break | —/150 | — | 54 | — |
| C: normal daily routine | — | 53 | — | ||
| total: | 120 | 107 | 89.2 | ||
| Jarani 2016 | I1: group circuit training‐based PE | —/767 | 261 | 253 | 96.9 |
| I2: games‐based PE | 251 | 243 | 96.8 | ||
| C: traditional PE school | 255 | 240 | 94.1 | ||
| total: | 767 | 736 | 96.0 | ||
| Kocken 2016 | I: theory and practical lessons on nutrition and PA | —/— | 615 | 367 | 59.7 |
| C: regular school programme or curriculum on nutrition and PA | 497 | 496 | 99.8 | ||
| total: | 1112 | 863 | 77.6 | ||
| Lau 2016 (RCT) | I: Xbox 260 Kinect gaming sessions after school | 152/84 | 40 | 40 | 100.0 |
| C: regular PA and PE class | 40 | 40 | 100.0 | ||
| total: | 80 | 80 | 100.0 | ||
| Resaland 2016 | I: physically active Norwegian, mathematics, and English lessons on the playground; PA breaks and PA homework | 1395/1202 | 620 | 593 | 95.6 |
| C: curriculum‐prescribed PE and PA | 582 | 530 | 91.1 | ||
| total: | 1202 | 1123 | 93.4 | ||
| Sutherland 2016 | I: 7 PA intervention strategies and 6 implementation strategies | —/1468 | 696 | 250 | 35.9 |
| C: only measurement components of the trial: regular PA and PE | 537 | 191 | 35.6 | ||
| total: | 1233 | 441 | 35.8 | ||
| Tarp 2016 | I: 60 minutes of PA during schooltime, PA homework | 869/855 | 215 | 194 | 90.2 |
| C: normal practice | 490 | 438 | 89.4 | ||
| total: | 705 | 632 | 89.6 | ||
| Cohen 2015 | I: teacher learning, PA policies, school‐community linkages | —/— | 199 | 166 | 83.4 |
| C: usual PE and school sport programmes | 261 | 217 | 83.1 | ||
| total: | 460 | 383 | 83.3 | ||
| Jago 2015 | I: after school dance classes | —/663 | 284 | — | — |
| C: provided data only | 287 | — | — | ||
| total: | 571 | 508 | 89.0 | ||
| Madsen 2015 | I: nutrition education curriculum, Playworks structured recess before or after school activities, PA and games implemented by teachers | —/— | 583 | 446 | 76.5 |
| C: — | 296 | 230 | 77.7 | ||
| total: | 879 | 676 | 76.9 | ||
| Muros 2015 | I1: extracurricular PA sessions | 242/162 | 28 | 28 | 100.0 |
| I2: PA and nutrition | 21 | 21 | 100.0 | ||
| I3: PA and nutrition and extra virgin olive oil during the final month | 25 | 25 | 100.0 | ||
| C1: nutrition and lifestyle education sessions | 41 | 41 | 100.0 | ||
| C2: usual activities | |||||
| total: | 135 | 135 | 100.0 | ||
| Suchert 2015 | I: multi‐level intervention targeting students, classrooms, schools, and parents | —/1489 | 790 | 702 | 88.9 |
| C: no intervention | 506 | 460 | 90.9 | ||
| total: | 1296 | 1162 | 89.7 | ||
| Andrade 2014 | I: ACTIVITAL individual‐ and environment‐based intervention | —/— | 700 | 550 | 78.6 |
| C: standard curriculum | 740 | 533 | 72.0 | ||
| total: | 1440 | 1083 | 75.2 | ||
| Jago 2014 | I: Action 3:30 activity club | —/— | 284 | 153 | 53.9 |
| C: schools provided data only | 255 | 157 | 61.6 | ||
| total: | 539 | 310 | 57.5 | ||
| Kipping 2014 | I: PA education intervention | 2242/2221 | 1064 | — | — |
| C: continued standard education provision | 1157 | — | — | ||
| total: | 2221 | 1252 | 56.4 | ||
| Kobel 2014 | I: teacher training, PA education, active breaks | 3159/1968 | — | — | — |
| C: no intervention | — | — | — | ||
| total: | 1964 | 1724 | 87.8 | ||
| Martinez‐Vizcaino 2014 (cluster‐RCT) | I: MOVI‐2 extracurricular PA programme | —/— | 769 | 420 | 54.6 |
| C: standard PE curriculum | 823 | 492 | 59.8 | ||
| total: | 1592 | 912 | 57.3 | ||
| Nogueira 2014 | I: high‐intensity capoeira sessions | 341/339 | 185 | 176 | 95.1 |
| C: usual school activities | 154 | 135 | 87.7 | ||
| total: | 339 | 138 | 40.7 | ||
| Santos 2014 | I: healthy buddies, healthy living lessons, structured aerobic exercise | —/— | 340 | 310 | 91.2 |
| C: standard curriculum | 347 | 273 | 78.7 | ||
| total: | 687 | 583 | 84.9 | ||
| Toftager 2014 | I: physical and organisational environmental changes | —/— | 623 | 551 | 88.4 |
| C: — | 725 | 608 | 83.9 | ||
| total: | 1348 | 1159 | 86.0 | ||
| Fairclough 2013 | I: weekly lesson plans, worksheets, homework tasks, lesson resources | 420/318 | 166 | 117 | 70.5 |
| C: normal instruction | 152 | 89 | 58.6 | ||
| total: | 318 | 196 | 61.6 | ||
| Ford 2013 (RCT) | I: accumulated brisk walking programme | —/174 | — | 77 | — |
| C: normal school lessons | — | 75 | — | ||
| total: | 174 | 152 | 87.4 | ||
| Grydeland 2013 | I: structured lessons, PA breaks, PA promotion | —/— | 784 | 519 | 66.2 |
| C: — | 1381 | 945 | 68.4 | ||
| total: | 2165 | 1464 | 67.6 | ||
| Melnyk 2013 | I: goal‐setting, education, PA homework | 1560/807 | 374 | 286 | 76.5 |
| C: Healthy Teens attention control curriculum was intended to promote knowledge of common adolescent health topics and health literacy | 433 | 341 | 78.8 | ||
| total: | 807 | 627 | 77.7 | ||
| Sacchetti 2013 | I: daily PA in schoolyard and classroom | 521/521 | 247 | 212 | 85.8 |
| C: standard programme of PE | 250 | 216 | 86.4 | ||
| total: | 497 | 428 | 86.1 | ||
| Siegrist 2013 | I: JuvenTUM educational and environmental intervention | —/902 | 486 | 427 | 87.9 |
| C: continued with usual school activities | 340 | 297 | 87.4 | ||
| total: | 826 | 724 | 87.7 | ||
| Aburto 2011 | I1: basic intervention of environmental and policy‐level changes | —/— | 262 | 241 | 92.0 |
| I2: plus intervention adding additional resources and daily morning exercise | 264 | 242 | 91.7 | ||
| C: no change to standard practices | 338 | 216 | 63.9 | ||
| total: | 864 | 699 | 80.9 | ||
| Ardoy 2011 | I1: 4 sessions/week of PE | 70/67 | 26 | 25 | 96.2 |
| I2: 4 sessions/week of PE with emphasis on increasing intensity | 23 | 23 | 100.0 | ||
| C: 2 sessions/week of PE | 18 | 18 | 100.0 | ||
| total: | 67 | 66 | 98.5 | ||
| de Heer 2011 | I: Bienstar intervention of health education and 45 to 60 minutes of after school PA | 1720/901 | 292 | 242 | 82.9 |
| C1: Grade 4 health workbooks and incentives | 251 | 236 | 94.0 | ||
| C2: spillover control group | 354 | 326 | 92.1 | ||
| total: | 897 | 804 | 89.6 | ||
| Jago 2011 | I: education, social marketing, food environment, PE curriculum, equipment provision | —/11158 | 5571 | 2060 | 37.0 |
| C: recruitment and data collection only | 5587 | 2003 | 35.9 | ||
| total: | 11158 | 4063 | 36.4 | ||
| Jansen 2011 | I: 3 PE sessions/week, additional after school sport and play, classroom education, parent health promotion | —/— | 1271 | 1149 | 90.4 |
| C: continued with usual curriculum | 1499 | 1267 | 84.5 | ||
| total: | 2770 | 2416 | 87.2 | ||
| Magnusson 2011 | I: students engaged in PA during PE lessons, during recess, and during classes; schools had access to PA equipment to use in school lessons; teaching materials promoting PA were provided | —/321 | 151 | 138 | 91.4 |
| C: followed the general PA curriculum | 170 | 116 | 68.2 | ||
| total: | 321 | 254 | 79.1 | ||
| Okely 2011 | I: PA action plan | —/1769 | 771 | 566 | 73.4 |
| C: continuation of usual programmes | 747 | 633 | 84.7 | ||
| total: | 1518 | 1199 | 79.0 | ||
| Thivel 2011 | I: 120 minutes of additional supervised PE | —/— | 229 | 229 | 100.0 |
| C: habitual 2 hours of PE/week | 228 | 228 | 100.0 | ||
| total: | 457 | 457 | 100.0 | ||
| Wilson 2011 | I: Active by Choice Today programme, PA homework, in‐school PA, motivational skills training | 729 | 673 | 92.3 | |
| C: General Health Education Programme | 693 | 635 | 91.6 | ||
| total: | 1422 | 1308 | 92.0 | ||
| Kriemler 2010 | I: 2 additional 45‐minute PE lessons/week, activity breaks, PA homework | 305 | 297 | 97.4 | |
| C: usual mandatory PE lessons | 235 | 205 | 87.2 | ||
| total: | 540 | 502 | 93.0 | ||
| Neumark‐Sztainer 2010 | I: New Moves curriculum (nutrition and self‐empowerment, motivational interviewing, lunch meetings, parent outreach) | 687 | 182 | 177 | 97.3 |
| C: participation in all‐girls PE class | 174 | 159 | 91.4 | ||
| total: | 356 | 336 | 94.4 | ||
| Angelopoulos 2009 | I: educational intervention covering self‐esteem, body image, nutrition, PA, fitness, and environmental issues, with motivational methods to increase knowledge, skills, self‐efficacy, self‐monitoring, and social influence | — | 321 | — | |
| C: — | — | 325 | — | ||
| total: | — | 646 | — | ||
| Donnelly 2009 | I: 90 minutes/week of moderate to | 814 | 792 | 97.3 | |
| C: regular classroom instruction | 713 | 698 | 97.9 | ||
| total: | 1527 | 1490 | 97.6 | ||
| Dorgo 2009 | I1: PE manual resistance training programme | 141 | 93 | 66.0 | |
| I2: PE manual resistance training plus | |||||
| C: regular PE programme that followed | 232 | 129 | 55.6 | ||
| total: | 373 | 222 | 59.5 | ||
| Gentile 2009 | I: 'Switch' programme: promoted | 670 | — | — | |
| C: no intentional exposure to the Switch programme | 653 | — | — | ||
| total: | 1323 | 1029 | 77.8 | ||
| Neumark‐Sztainer 2009 | I: after school theatre sessions, booster | 56 | 51 | 91.1 | |
| C: a theatre‐based control condition | 52 | 45 | 86.5 | ||
| total: | 108 | 96 | 88.9 | ||
| Peralta 2009 (RCT) | I: curriculum and peer‐facilitated | 16 | 16 | 100.0 | |
| C: PA curriculum | 17 | 16 | 94.1 | ||
| total: | 33 | 32 | 97.0 | ||
| Walther 2009 | I: 1 unit of physical exercise (45 minutes) | 112 | 109 | 97.3 | |
| C: German standards, 2 units (each 45 | 76 | 73 | 96.1 | ||
| total: | 188 | 182 | 96.8 | ||
| Reed 2008 | I: Action Schools!BC whole‐school PA | 178 | 156 | 87.6 | |
| C: regular programme of PE and | 90 | 81 | 90.0 | ||
| total: | 268 | 237 | 88.4 | ||
| Salmon 2008 | I: 1, 2, 3 behavioural modification group; fundamental motor skills group; combined behavioural modification and fundamental motor skills group | 233 | 213 | 91.4 | |
| C: usual classroom lessons | 62 | 55 | 88.7 | ||
| total: | 295 | 268 | 90.8 | ||
| Wang 2008 | I: 'FitKid' after school intervention sessions | 603 | 260 | 43.1 | |
| C: — | 584 | 265 | 45.4 | ||
| total: | 1187 | 525 | 44.2 | ||
| Webber 2008 | I: health education lessons to enhance | — | — | — | |
| C: — | — | — | — | ||
| total: | 3502 | 3378 | 96.5 | ||
| Weeks 2008 (RCT) | I: directed jumping activity at the beginning | 52 | 43 | 82.7 | |
| C: regular PE warm‐ups and stretching | 47 | 38 | 80.9 | ||
| total: | 99 | 81 | 81.8 | ||
| Barbeau 2007 (RCT) | I: after school PA programme | — | — | 81 | |
| C: — | — | — | 84 | ||
| total: | — | — | — | ||
| Williamson 2007 | I: Healthy Eating and Exercise programme | 313 | 282 | 90.1 | |
| C: Alcohol/Drug/Tobacco abuse prevention | 348 | 304 | 87.4 | ||
| total: | 661 | 586 | 88.7 | ||
| Haerens 2006 | I1: a computer‐tailored intervention | 2105 | — | — | |
| I2: group 1 plus parental involvement | |||||
| C: no PA and nutrition intervention | 735 | — | — | ||
| total: | 2840 | 2434 | 85.7 | ||
| Young 2006 (RCT) | I: PE curriculum taught 5 days/week | 116 | 111 | 95.7 | |
| C: standard PE class | 105 | 99 | 94.3 | ||
| total: | 221 | 210 | 95.0 | ||
| Bayne‐Smith 2004 (RCT) | I: Physical Activity and Teenage Health | — | 310 | — | |
| C: same frequency or duration of PE | — | 132 | — | ||
| total: | — | 442 | — | ||
| Simon 2004 | I: an educational component focusing | — | 475 | — | |
| C: — | — | 479 | — | ||
| total: | 1046 | 954 | 91.2 | ||
| Trevino 2004 | I: health programming regarding 3 | 969 | 619 | 63.9 | |
| C: — | 1024 | 602 | 58.8 | ||
| total: | 1993 | 1221 | 61.3 | ||
| Stone 2003 | I: food service, skills‐based classroom | 879 | 644 | 73.3 | |
| C: — | 825 | 653 | 79.2 | ||
| total: | 1704 | 1297 | 76.1 | ||
| Burke 1998 | I1: standard PA and nutrition programme | — | — | — | |
| I2: I1 plus a PA enrichment programme | |||||
| C: no programme | — | — | — | ||
| total: | 800 | 720 | 90.0 | ||
| Ewart 1998 (RCT) | I: 50‐minute 'Project Heart' aerobic exercise classes | 45 | 44 | 97.8 | |
| C: 50‐minute standard PE classes | 54 | 44 | 81.5 | ||
| total: | 99 | 88 | 88.9 | ||
| Luepker 1996 | I1: school food service modifications, | 3651 | 3297 | 90.3 | |
| I2: I1 plus a family‐based programme | |||||
| C: usual health curricula, PE, and food | 1455 | 722 | 49.6 | ||
| total: | 5106 | 4019 | 78.7 | ||
| Bush 1989 | I1: 'Know Your Body' curriculum focusing | — | — | — | |
| I2: 'Know Your Body' curriculum and | |||||
| C: health screening only | — | — | — | ||
| total: | 892 | 431 | 48.3 | ||
| Walter 1988 | I: special curriculum targeting voluntary | — / 3388 | 2075 | 1104 | 53.2 |
| C: — | 1313 | 665 | 50.6 | ||
| total: | 3388 | 1769 | 52.2 | ||
| Grand total | All interventions | 46 073 | 28 089 | ||
| All c omparators | 40 566 | 23 639 | |||
| All interventions and c omparators b | 96 740 | 66 752 | |||
| —: denotes not reported. aFollow‐up under randomised conditions until end of trial (= duration of intervention + follow‐up post intervention or identical to duration of intervention); extended follow‐up refers to follow‐up of participants once the original trial was terminated as specified in the power calculation. bNote that numbers from all interventions and all interventions and comparators are greater than the sum of interventions only and comparators only, as some studies reported only the total number of included participants and did not note numbers within each group. C: comparator; I: intervention; MVPA: moderate to vigorous physical activity; NA: not applicable; PA: physical activity; PE: physical education; RCT: randomised controlled trial. | |||||
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
| 1.1 Physical activity participation: all data Show forest plot | 5 | Other data | No numeric data | |
| 1.1.1 Children: before and after school programme | 1 | Other data | No numeric data | |
| 1.1.2 Children: schooltime PA | 1 | Other data | No numeric data | |
| 1.1.3 Children: multi‐component interventions | 1 | Other data | No numeric data | |
| 1.1.4 Adolescents: multi‐component interventions | 2 | Other data | No numeric data | |
| 1.2 Physical activity duration (minutes/d): meta‐analysis Show forest plot | 33 | 20614 | Mean Difference (IV, Random, 95% CI) | 0.73 [0.16, 1.30] |
| 1.2.1 Children | 22 | 10715 | Mean Difference (IV, Random, 95% CI) | 1.01 [0.08, 1.93] |
| 1.2.2 Adolescents | 11 | 9899 | Mean Difference (IV, Random, 95% CI) | 1.84 [0.34, 3.35] |
| 1.3 Physical activity duration by intervention type (minutes/d): meta‐analysis Show forest plot | 33 | 20614 | Mean Difference (IV, Random, 95% CI) | 0.73 [0.16, 1.30] |
| 1.3.1 Before and after school programmes | 6 | 2571 | Mean Difference (IV, Random, 95% CI) | 0.77 [‐1.40, 2.94] |
| 1.3.2 Enhanced PE | 3 | 2050 | Mean Difference (IV, Random, 95% CI) | ‐0.23 [‐1.58, 1.11] |
| 1.3.3 Multi‐component interventions | 16 | 12135 | Mean Difference (IV, Random, 95% CI) | 2.42 [0.62, 4.22] |
| 1.3.4 Schooltime PA | 8 | 3858 | Mean Difference (IV, Random, 95% CI) | 5.30 [0.89, 9.72] |
| 1.4 Physical activity duration: additional data Show forest plot | 6 | Other data | No numeric data | |
| 1.4.1 Before and after school programmes | 1 | Other data | No numeric data | |
| 1.4.2 Enhanced PE | 2 | Other data | No numeric data | |
| 1.4.3 Multi‐component intervention | 2 | Other data | No numeric data | |
| 1.4.4 Schooltime PA | 2 | Other data | No numeric data | |
| 1.5 Sedentary time (minutes/d): meta‐analysis Show forest plot | 16 | 11914 | Mean Difference (IV, Random, 95% CI) | ‐3.78 [‐7.80, 0.24] |
| 1.5.1 Children | 11 | 5766 | Mean Difference (IV, Random, 95% CI) | ‐3.35 [‐9.30, 2.60] |
| 1.5.2 Adolescents | 5 | 6148 | Mean Difference (IV, Random, 95% CI) | ‐5.67 [‐11.48, 0.14] |
| 1.6 Sedentary time (minutes/d) by intervention type: meta‐analysis Show forest plot | 16 | 11914 | Mean Difference (IV, Random, 95% CI) | ‐3.78 [‐7.80, 0.24] |
| 1.6.1 Before and after school programmes | 2 | 773 | Mean Difference (IV, Random, 95% CI) | 2.01 [‐15.28, 19.31] |
| 1.6.2 Enhanced PE | 1 | 540 | Mean Difference (IV, Random, 95% CI) | ‐11.18 [‐21.96, ‐0.40] |
| 1.6.3 Multi‐component interventions | 11 | 9164 | Mean Difference (IV, Random, 95% CI) | ‐4.60 [‐9.08, ‐0.12] |
| 1.6.4 Schooltime PA | 2 | 1437 | Mean Difference (IV, Random, 95% CI) | ‐3.26 [‐19.05, 12.52] |
| 1.7 Sedentary time: additional data Show forest plot | 4 | Other data | No numeric data | |
| 1.7.1 Before and after school programmes | 1 | Other data | No numeric data | |
| 1.7.2 Enhanced PE | 3 | Other data | No numeric data | |
| 1.7.5 Multi‐component intervention | 1 | Other data | No numeric data | |
| 1.8 Physical fitness (mL/kg/min): meta‐analysis Show forest plot | 13 | 3980 | Mean Difference (IV, Random, 95% CI) | 1.19 [0.57, 1.82] |
| 1.8.1 Children | 9 | 2215 | Mean Difference (IV, Random, 95% CI) | 1.47 [0.84, 2.09] |
| 1.8.2 Adolescents | 4 | 1765 | Mean Difference (IV, Random, 95% CI) | 0.58 [‐0.18, 1.35] |
| 1.9 Physical fitness (mL/kg/min) by intervention type: meta‐analysis Show forest plot | 13 | 3980 | Mean Difference (IV, Random, 95% CI) | 1.19 [0.57, 1.82] |
| 1.9.1 Before and after school programmes | 5 | 724 | Mean Difference (IV, Random, 95% CI) | 1.38 [0.34, 2.41] |
| 1.9.2 Enhanced PE | 4 | 1387 | Mean Difference (IV, Random, 95% CI) | 1.99 [0.76, 3.21] |
| 1.9.3 Multi‐component interventions | 3 | 1697 | Mean Difference (IV, Random, 95% CI) | ‐0.33 [‐0.73, 0.08] |
| 1.9.4 Schooltime PA | 1 | 172 | Mean Difference (IV, Random, 95% CI) | 2.70 [1.04, 4.36] |
| 1.10 Physical fitness: additional data Show forest plot | 29 | Other data | No numeric data | |
| 1.10.1 Before or after school programme | 4 | Other data | No numeric data | |
| 1.10.2 Enhanced PE | 5 | Other data | No numeric data | |
| 1.10.3 Multi‐component intervention | 11 | Other data | No numeric data | |
| 1.10.4 Schooltime PA | 10 | Other data | No numeric data | |
| 1.11 BMI: meta‐analysis [z‐scores] Show forest plot | 21 | 22948 | Mean Difference (IV, Random, 95% CI) | ‐0.06 [‐0.09, ‐0.02] |
| 1.11.1 Children | 16 | 15732 | Mean Difference (IV, Random, 95% CI) | ‐0.06 [‐0.11, ‐0.01] |
| 1.11.2 Adolescents | 5 | 7216 | Mean Difference (IV, Random, 95% CI) | ‐0.03 [‐0.05, ‐0.00] |
| 1.12 BMI by intervention type: meta‐analysis [z‐scores] Show forest plot | 21 | 22948 | Mean Difference (IV, Random, 95% CI) | ‐0.06 [‐0.09, ‐0.02] |
| 1.12.1 Before and after school programmes | 2 | 1615 | Mean Difference (IV, Random, 95% CI) | ‐0.02 [‐0.05, 0.01] |
| 1.12.2 Enhanced PE | 1 | 174 | Mean Difference (IV, Random, 95% CI) | ‐0.08 [‐0.29, 0.13] |
| 1.12.3 Multi‐component interventions | 17 | 19489 | Mean Difference (IV, Random, 95% CI) | ‐0.06 [‐0.11, ‐0.01] |
| 1.12.4 Schooltime PA | 1 | 1670 | Mean Difference (IV, Random, 95% CI) | ‐0.03 [‐0.08, 0.02] |
| 1.13 BMI: meta‐analysis [kg/m2] Show forest plot | 50 | 34337 | Mean Difference (IV, Random, 95% CI) | ‐0.07 [‐0.15, 0.01] |
| 1.13.1 Children | 38 | 25447 | Mean Difference (IV, Random, 95% CI) | ‐0.11 [‐0.19, ‐0.02] |
| 1.13.2 Adolescents | 12 | 8890 | Mean Difference (IV, Random, 95% CI) | 0.05 [‐0.16, 0.25] |
| 1.14 BMI by intervention type: meta‐analysis [kg/m2] Show forest plot | 50 | 34337 | Mean Difference (IV, Random, 95% CI) | ‐0.07 [‐0.15, 0.01] |
| 1.14.1 Before and after school programmes | 9 | 2314 | Mean Difference (IV, Random, 95% CI) | ‐0.12 [‐0.25, 0.01] |
| 1.14.2 Enhanced PE | 10 | 3357 | Mean Difference (IV, Random, 95% CI) | ‐0.04 [‐0.32, 0.24] |
| 1.14.3 Multi‐component interventions | 20 | 24417 | Mean Difference (IV, Random, 95% CI) | ‐0.10 [‐0.24, 0.03] |
| 1.14.4 Schooltime PA | 11 | 4249 | Mean Difference (IV, Random, 95% CI) | ‐0.05 [‐0.14, 0.04] |
| 1.15 BMI: additional data Show forest plot | 9 | Other data | No numeric data | |
| 1.15.1 Before or after school programme | 1 | Other data | No numeric data | |
| 1.15.2 Enhanced PE | 1 | Other data | No numeric data | |
| 1.15.3 Multi‐component intervention | 4 | Other data | No numeric data | |
| 1.15.4 Schooltime PA | 3 | Other data | No numeric data | |
| 1.16 Health‐related quality of life: all data Show forest plot | 7 | Other data | No numeric data | |
| 1.16.1 Children | 5 | Other data | No numeric data | |
| 1.16.2 Adolescents | 2 | Other data | No numeric data | |
| 1.17 Adverse events: all data Show forest plot | 16 | Other data | No numeric data | |
