Physical activity

In general physical activity, also called motor activity, is "any bodily movement produced by skeletal muscles that requires energy expenditure."

Exercise is "physical activity which is usually regular and done with the intention of improving or maintaining physical fitness or health."

Physiology

In physiology physical activity is "the physical activity of a human or an animal as a behavioral phenomenon."

Promoting physical activity

Promoting physical activity is difficult; a systematic review found "the most effective interventions were behavioral interventions instead of cognitive interventions, face-to-face delivery versus mediated interventions (e.g., via telephone or mail), and targeting individuals instead of communities."

Simple interventions might help.