VO2max

VO2max represents a physiological ceiling on the body's capacity to increase oxygen uptake, oxygen transport and oxygen use in response to a rising workload [1]. It is accepted as the gold standard measure of cardiorespiratory fitness [1].

It is usually measured during an incremental exercise test to exhaustion on a cycle ergometer or treadmill, with oxygen uptake worked out from the gases a person breathes in and out (indirect calorimetry) [1][2]. Results are given in liters per minute or in milliliters per kilogram of body weight per minute; among 1,680 apparently healthy adults aged 19 to 68 in the studies one review included, the average was 3.3 L/min (standard deviation 1.4) or 46.9 mL/kg/min (standard deviation 12.1) [2]. These were study volunteers, not a reference norm.

Confirming that a test reached a true maximum is not simple. The classic sign is a plateau, little or no further rise in oxygen uptake while the workload keeps increasing [2]. That plateau appears inconsistently, and secondary criteria, such as percentages of maximal heart rate, depend heavily on the test protocol [1].

Some laboratories append a verification bout after the main test to confirm the maximum, but procedures for it are not standardized [1][2]. A meta-analysis of 54 studies found that the highest oxygen uptake in the main test and in the verification phase were similar [2]. Its authors called the verification phase a robust way to confirm the maximum but questioned whether it is needed in every testing situation [2].

A supplement trial that reports VO2max has measured aerobic capacity in a lab test, compared with placebo or another control. NootropicsWork reports VO2max findings with the population, the test type and the comparison.

Ergogenic aid, meta-analysis, placebo.