What is VO2 and VO2 Max?

VO2 (or oxygen consumption) is a measure of the volume of oxygen that is used by your body to convert the energy from the food you eat into the energy molecules, called adenosine triphosphate (ATP), that your body uses at the cellular level. VO2max (or maximal oxygen consumption) is simply the maximum possible VO2 that a given person can achieve. VO2 and VO2max are important in the context of exercise, because they are a measure of your body’s ability to generate ATP, and ATP is the energy source that allows your muscles to continue working while you are exercising. Therefore, by definition, a VO2max measurement is ultimately a measure of your cardiorespiratory fitness level. VO2max, or maximum oxygen consumption, is an index of physical fitness and a measure of the maximum amount of oxygen that the body can utilize during exercise. Generating the energy needed in the muscles during exercise requires oxygen. Transporting oxygen from the outside air to the muscles involves the integrated function of several parts of the body, including the lungs, heart, blood, blood vessels, and the muscles which are the engines that produce the energy to do the physical work. Regular physical activity increases the body’s ability to transport and utilize oxygen. This results in improved exercise tolerance and VO2 max, reflecting better fitness and aerobic capacity.

Andrew L. Ries