Aerobic Exercise – The American College of Sports Medicine defines aerobic exercise as: “Any activity that involves large muscle groups, can last for a long time, and is rhythmic in nature.” Aerobic is defined as exercise that takes place in the presence or absence of oxygen. Your body burns its fuel (glucose), in the presence oxygen. This is done at less than 85% your maximum heart rate. Aerobically fit individuals can work harder, longer and recover faster after each session. Aerobic exercise can be done in a variety of ways, including swimming, biking, rowing, aerobics classes and swimming.