http://activelivingresearch.org/do-short-physical-activity-breaks-classrooms-work

Creating activity breaks at school, such as moving and stepping for up to 20 minutes at a time in the classroom during the school day, is a relatively new and innovative method for increasing physical activity among children. This brief summarizes the research on how programs that provide classroom physical activity breaks impact physical activity, on-task behavior, health, and related factors in children. Active Living Research, February 2013.