Increased levels of physical activity are associated with improved health. However, the determinants of an active lifestyle are unknown. Participation in school sports and physical education during childhood and adolescence are frequently mentioned as factors likely to promote more active lifestyles in adulthood. If this is true, public policy should more vigorously promote broad participation in school sports and physical education. However, review of the available literature reveals only six papers that address this issue directly, and all six have important methodological limitations. The study that provides the strongest support provides information only on sports participation during college, an age at which behavior patterns may already be firmly established. Therefore, more research in this area is needed. Future studies must consider definitions, confounding variables, recall bias, selection bias, content, and quality of school sports and physical education programs.