Class 16 note exercise for health and fitness. What is physical activity: any bodily movement produced by skeletal muscles that requires energy expenditure, we often use physical activity and exercise interchangeably but exercise is technically a subset of physical activity. Psychological benefits of exercise: decrease state and trait anxiety, decrease depression. Increase muscular and cardiorespiratory fitness: decrease risk of hypertension, coronary heart disease, stroke, diabetes, breast and colon cancer, decrease risk of falls and hip or vertebral factures, weight control and energy balance. Prevalence of physical activity: approximately 47% of canadian adults are inactive, more men (55%) than women (51%) are active, globally, at least 1 in 4 adults fails to achieve the minimum recommendation of daily physical activity. What about university students: approximately 50% of north american university students are insufficiently active. Are people sticking to it : approximately 20-50% of adults who begin an exercise program withdraw within the first 6 months.