The maximum value of oxygen uptake, transport and use during exercise is a good indicator of the functioning of respiratory, cardiovascular and muscle-skeletal systems. In sports science this is called VO2max.

VO2max has been considered the main reference standard for cardiorespiratory fitness. It is considered by sports physiologists as synonymous with aerobic conditioning. In aerobic endurance sports, a high capacity to consume oxygen is a prerequisite for success. Its measurement is usually expressed in liters per minute or milliliters of oxygen used in one minute per kilogram of body weight (ml/kg/min).