The effectiveness of school based interventions in promoting physical activity and fitness among children and youth: A systematic review

Objective: 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. Methods: Databases searched included MEDLINE, CINAHL, PsycInfo, Sociological Abstracts, SportDiscus, Dissertation Abstracts, ERIC, and EMBASE from 1985 to July 2007. Search terms included school, physical activity, exercise, physical fitness, physical education, effectiveness, efficacy, evaluation, outcome, impact, and evidence. Search results were further limited to children and adolescents aged 6-18 years. The reference lists of relevant articles were reviewed for additional articles. Standardized tools were used by two independent reviewers to rate each study for relevance, methodological quality, and data extraction. Where discrepancies existed discussion occurred until consensus was reached. Results: 41,506 titles were identified and screened and 283 articles were retrieved. Multiple publications on the same project were combined and counted as one project, resulting in 170 distinct project accounts (studies). Of the 170 studies 104 were deemed relevant and of those, 4 were assessed as having strong methodological quality, 22 were of moderate quality and 78 were considered weak. In total 26 individual studies were included in the review. There is good evidence that school-based physical activity interventions are effective in increasing duration of physical activity and VO2 Max, and reducing blood cholesterol and time spent watching television. However the evidence suggests school-based interventions are not effective in increasing the percentage of children and adolescents who are physically active, or in reducing systolic and diastolic blood pressure, BMI, and pulse rate. At a minimum, printed educational materials and changes to the school curriculum that result in increases in physical activity were shown to be effective strategies. Conclusion: Given that there are no harmful effects and that there was evidence of positive effects on some lifestyle behaviours and physical health status measures, ongoing physical activity promotion in schools is recommended at this time. Furthermore, it is likely that many health status indicators are inappropriate measures of the effectiveness of school-based interventions. The variability in these findings may be indicative of the limitations and difficulties inherent in doing community-based research where randomization to treatment groups, blind assessment, and co-intervention are difficult to control. Additional research is needed to evaluate the long term impact of these interventions.