interrelated terms are used to describe physical activity in the literature, including exercise, regular physical activity, specific activities such as walking, and leisure time physical activity. Physical activity is defined as engaging in a body of movements produced by skeletal muscles that result in energy expenditure above the basal level. Leisure time physical activity is defined as participating in physically active hobbies or sports or exercising within a 2- week period. These measures are typically based on self-reports and are used in national surveys and ongoing surveillance. The types of exercises used to qualify the types of movement can be classified as aerobic, strength and resistance training, range of motion, or balance. Regular physical activity is a lifestyle, exercise is a behavior, and the terms are not interchangeable.