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Do school‐based physical activity interventions increase moderate to vigorous physical activity and improve physical fitness among children and adolescents?

Key messages

School‐based interventions may improve physical fitness but may have little to no impact on body mass index (which is used to assess whether body weight is in a healthy range), although we do not have confidence in the evidence. 

Very few studies have reported on any potential harmful effects. 

Careful consideration is needed about the type of school‐based physical activity programme to be implemented, and future studies should seek to identify the best types of physical activity interventions for school settings.

Why is it important to promote physical activity in children?

It is estimated that as many as 5.3 million deaths worldwide are caused by not getting enough exercise (physical inactivity), and this is a big risk factor leading to most long‐lasting diseases and cancers. This is a topic of concern, particularly because it is known that physical activity patterns in childhood can lead to similar patterns in adulthood. Programmes that encourage children to exercise while at school are thought to be a way to increase activity levels of all children, regardless of other factors such as parent behaviours and social or financial factors of a child’s early lifetime. 

What did we find?

We found 89 studies that looked at the effects of programmes in schools that focused on increasing physical activity, which included 66,752 children and adolescents (between the ages of 6 and 18) from around the world. The length of programme time varied from 12 weeks to 6 years. No two school‐based physical activity programmes used the same combination of intervention parts. How often and how long each part of a programme was run varied a lot across studies.

Across all included studies, only very small changes were noted in the number of students undertaking physical activity or in minutes per day of moderate to vigorous physical activity or sedentary time, although these programmes were found to improve students’ physical fitness. These programmes were found to have little to no impact on measurements used to assess whether body weight is in a healthy range. Not many studies reported on any potential harmful effects, such as injury or psychological harm. 

What are the limitations of the evidence?

We have little confidence in the evidence because studies were done in different ways and interventions were delivered and assessed in different ways. Also, people in the studies may have been aware of which interventions they were getting, and this can sometimes affect the outcomes reported. In addition, not all studies provided data about everything we were interested in.

How up‐to‐date is the evidence? 

The evidence is up‐to‐date to June 2020 (although we did run a new search for studies in February 2021 and found studies that may be included in a future update and are now described in the “Studies awaiting classification” table).

Read the full review here