Examines the effects of physical activity on depression and anxiety, discussing the scientific strength of studies on physical activity, depression, and anxiety against the standards of science accepted in epidemiology with a focus on the independence, consistency, dose-response gradient, and biological plausibility of the evidence. (Author/SM)

Discusses physical activity and exercise adherence, describing five conundrums that retard advances in knowledge about causal determinants of physical activity and successful interventions that increase physical activity and exercise adherence: adoption versus maintenance; social marketing versus product marketing; mediators of physical activity;…