VO2 Max

Unit: mL/kg/min

VO2 max represents maximal oxygen uptake—the maximum rate at which the body can consume oxygen during intense exercise. Expressed in mL/kg/min, it is the gold-standard measure of cardiorespiratory fitness. Average values are 35-40 mL/kg/min for men and 27-31 for women, declining with age. Elite endurance athletes may exceed 70-85 mL/kg/min. Higher VO2 max correlates strongly with reduced all-cause mortality and cardiovascular disease risk. Wearables estimate VO2 max using heart rate response during submaximal exercise, age, and sometimes running pace—accuracy is ±10-15% compared to laboratory testing. Improvements of 10-20% are achievable with consistent aerobic training. Clinical applications include assessing cardiac rehabilitation progress and surgical risk stratification.