The ability of a person to increase oxygen uptake above his or her oxygen uptake at rest. While lying comfortably in bed each individual’s body uses a basal (resting) level of oxygen to perform basic metabolic functions. This level of oxygen usage is referred to as one metabolic equivalent, or informally, as 1 MET. While walking on level ground the average person doubles his oxygen uptake, that is, his oxygen uptake increases to 2 MET. Higher levels of exercise (such as jogging) can only be achieved by individuals with greater exercise capacity; jogging at 6 miles per hour requires 6 MET. Highly trained athletes can achieve 15 MET or more. Studies have shown that the lower one’s exercise capacity, the more likely that person is to die from heart disease.