Aerobic zone: when you are exercising at an intensity where your heart rate raises to 60-85% of maximum heart rate. Aerobic exercise: endurance exercise that increases heart rate and uses oxygen to provide energy as atp. Aerobic capacity: maximum amount of oxygen that can be consumed by the tissues during exercise. Also called maximal oxygen consumption or vo2 max. Anabolic steroids: synthetic fat-soluble hormones that mimic testosterone and are used to increase muscle strength and mass. Cardiorespiratory endurance: efficiency with which the body delivers to cells the oxygen and nutrients needed for muscular activity and transports waste products from cells. Carb, fat, and protein needs: 6-10g of carb/kg of body weight per day recommended for athletes. Carbohydrate loading: regimen designed to increase muscle glycogen stores beyond their usual level (373) Chronic disease: exercise can reduce risk of cardiovascular disease, hypertension, type 2 diabetes, breast and colon cancer, and bone and joint disorders. Components of fitness: endurance, strength, flexibility, body composition.