• Most American youth are not meeting the 60 minutes per day recommendation for moderate- to vigorous- intensity physical activity (MVPA). The CDC Community Guide and School Health Guidelines to Promote Healthy Eating and Physical Activity Guides both suggest that policy and built environment changes will affect everyone exposed to a given environment and will have long lasting effects.
• The authors seek to provide policymakers with information for more informed decisions by quantifying the increase in energy expenditure due to school-based policies and built environment changes
• For this review, scientific studies evaluating policy and/or built environment changes  were identified and 85 of 300 studies published in English  were selected. The impact of various strategies for increasing physical activity in youth was estimated from objective measurements or direct observation. 
• Within school settings, the average minutes of MVPA gained per school day for studies in each intervention category were as follows:
• School settings: Mandatory physical education (23 minutes); Classroom activity breaks (19 minutes);  Afterschool activity programs (10 minutes); Standardized physical education curricula (6 minutes more than traditional physical education); Modifıed playgrounds (6 minutes);  Modifıed recess (5 minutes more than traditional recess)
• Community Setting: Active commuting (16 minutes); Park renovations (12 minutes); Proximity to parks (1 minute). No conclusions could be drawn regarding joint-use agreements, because of a lack of studies quantifying their impact on energy expenditure.
• The largest effects were seen with mandatory physical education, classroom activity breaks, and active commuting to school. Policymakers can use this information along with estimates of the cost, feasibility, and population reach, to identify the best options for increasing physical activity in youth.

David R. Bassett, PhD, Eugene C. Fitzhugh, PhD, Gregory W. Heath, DHSc, MPH, Paul C. Erwin, MD, DrPH, Ginny M. Frederick, MS, Dana L. Wolff, MS, Whitney A. Welch, MS, Aaron B. Stout, MS. (2013). Estimated Energy Expenditures for School-Based Policies and Active Living. Am J Prev Med, 44(2), 108-113.