Cochrane review: School‐based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6‐18
Authors: Dobbins Maureen , DeCorby Kara , Robeson Paula , Husson Heather , Tirilis Daiva 
Published: December 2009

Background

The World Health Organization estimates that 1.9 million deaths worldwide are attributable to physical inactivity. Chronic diseases associated with physical inactivity include cancer, diabetes and coronary heart disease.

Objectives

The purpose of this systematic review is to summarize the evidence of the effectiveness of school‐based interventions in promoting physical activity and fitness in children and adolescents.

Search strategy

The search strategy included searching several databases. In addition, reference lists of included articles and background papers were reviewed for potentially relevant studies, as well as references from relevant Cochrane reviews. Primary authors of included studies were contacted as needed for additional information.

Selection criteria

To be included, the intervention had to be relevant to public health practice, implemented, facilitated, or promoted by staff in local public health units, implemented in a school setting and aimed at increasing physical activity, report on outcomes for children and adolescents (aged 6 to 18 years), and use a prospective design with a control group.

Data collection and analysis

Standardized tools were used by two independent reviewers to rate each study's methodological quality and for data extraction. Where discrepancies existed discussion occurred until consensus was reached. The results were summarized narratively due to wide variations in the populations,  interventions evaluated and outcomes measured.

Main results

13,841 titles were identified and screened and 482 articles were retrieved. Multiple publications on the same project were combined and counted as one project, resulting in 395 distinct project accounts (studies). Of the 395 studies 104 were deemed relevant and of those, four were assessed as having strong methodological quality, 22 were of moderate quality and 78 were considered weak. In total 26 studies were included in the review. There is good evidence that school‐based physical activity interventions have a positive impact on four of the nine outcome measures. Specifically positive effects were observed for  duration of physical activity, television viewing,  VO2max, and blood cholesterol. Generally school‐based  interventions had no  effect on leisure time physical activity rates,  systolic and diastolic blood pressure, body mass index, and pulse rate. At a minimum, a combination of printed educational materials and changes to the school curriculum that promote physical activity result in positive effects.

Authors' conclusions

Given that there are no harmful effects and that there is some evidence of positive effects on lifestyle behaviours and physical health status measures, ongoing physical activity promotion in schools is recommended at this time.

Plain Language Summary

School‐based interventions for promoting physical activity and fitness in children and adolescents

Current evidence suggests that school‐based physical activity interventions may be effective in the development of healthy lifestyle behaviours among children and adolescents that will then translate into reduced risk for many chronic diseases and cancers in adulthood. The evidence also suggests that the best primary strategy for improving the long‐term health of children and adolescents through exercise may be creating lifestyle patterns of regular physical activity that carry over to the adult years.

It is estimated that as many at 1.9 million deaths worldwide are attributable to physical inactivity, and that inactivity is a key risk factor in the development of most chronic diseases and cancers.

This is alarming particularly because it is known that physical activity patterns track from childhood into adulthood; that children are increasingly exhibiting risk factors for cardiovascular disease, such as obesity, elevated blood lipids, and hypertension, conditions which are known to track into adulthood; and that atherosclerotic fatty streaks in the coronary arteries, which are indicative of coronary heart disease, have been found postmortem in children.

This review included 26 studies that evaluated the impact of combinations of school‐based interventions focused on increasing physical activity among children and adolescents. Participants were between the ages of 6 to18 living in Australia, South America, Europe and North America.

There is good evidence that school‐based physical activity interventions are effective in increasing duration of physical activity, reducing blood cholesterol and time spent watching television and increasing VO2max. VO2max, known as maximal oxygen uptake or aerobic capacity, reflects the physical fitness level of an individual and generally increases as fitness levels improve. These interventions are not effective in increasing the percentage of children and adolescents who are physically active during leisure time, or in reducing systolic and diastolic blood pressure, body mass index, and pulse rate. At a minimum, a combination of printed educational materials and changes to the school curriculum that promote physical activity result in positive effects for four of the nine outcomes.