ABSTRACT
By denition, maximal aerobic power is the highest oxygen intake (VO2max) a person can achieve during exercise and is bounded by the parametric limits of the Fick equation (stroke volume × heart rate × [arterial oxygen − venous oxygen]). Consequently, the absolute value of VO2max, typically expressed in liters per minute (L·min−1), characterizes cardiovascular function because it highly correlates with cardiac output.3,58 Absolute values may range from as low as 1.0 L·min−1 (or lower with cardiovascular disease) to as high as 6 L·min−1 (or even higher in large, well-trained individuals). Because two individuals of different body weights can have the same absolute values, VO2max is usually normalized for body weights (and expressed as mL·kg−1·min−1) to allow for comparisons between and among different persons. For example, if two men have absolute values of 4.2 L·min−1, but one weighs 70 kg and the other 95 kg, then their VO2max values normalized for body weight would be 60 mL·kg−1·min−1
for the 70 kg man and 44.2 mL·kg−1·min−1 for the 95 kg man. This relative VO2max provides an indication of an individual’s potential for work-particularly tasks that involve running and climbing-and overall endurance. So, the man who weighs only 70 kg is in better shape for physical work because his relative effort at a work level demanding an oxygen intake (VO2) of 40 mL·min−1 would only be 66% of his VO2max, whereas the 95 kg man would be operating at 90% of his VO2max. Table 27.2 presents normative data by age and gender from the Cooper Institute; this allows VO2max values to be compared and interpreted in light of the general population.
