VO2 max, or maximal oxygen consumption, refers to the maximum amount of oxygen that an individual can utilize during intense or maximal exercise. This measurement is generally considered the best indicator of cardiovascular fitness and aerobic endurance. The more oxygen a person can use during high intensity exercise, the more energy a person can produce. This test is the gold standard for determining cardiorespiratory fitness because the muscles need oxygen for prolonged aerobic exercise. Following the test clients leave with an accurate measurement of his/her current fitness level and a plan to improve their fitness level.