Physical activity opportunities in schools take the form primarily of formal instruction in physical education for all students and sport-based athletics for the talented and interested. Although physical education is a required school subject, the classes may occur infrequently, and children taking them often accrue only low levels of physical activity. Schools have the potential to influence the physical activity behaviors of their students through various opportunities in addition to physical education (e.g., recess periods and classroom physical activity breaks). Thus it is essential for the school setting to provide opportunities outside of physical education for school-age children to be physically activity throughout the school day.