VO2 stands for the volume of oxygen that the body utilizes each minute. VO2 max or maximal oxygen uptake or peak oxygen uptake or maximal aerobic capacity is the maximum rate of oxygen consumption measured during exercise of increasing intensity (incremental exercise). Laboratory measured VO2 max provides a quantitative value of endurance fitness and reflects cardiorespiratory fitness and endurance capacity. VO2 max is expressed either as an absolute rate in litres of oxygen per minute (L/min) or as a relative rate in millilitres of oxygen per kilogram of body mass per minute (mL/(kg/min). Elite athletes have VO2 max values of around 90 mL/kg/min. Lower fitness levels are associated with high risk of cardiovascular disease, all-cause mortality, and mortality rates stemming from various types of cancers. Source: