Influence of body mass on maximal oxygen uptake: effect of sample size

Basal metabolic rate is scaled to body mass to the power of 0.73, and we ev aluated whether a similar scaling applies when the O-2 transport capacity o f the body is challenged during maximal exercise (i.e. at maximal O-2 uptak e, VO2max). The allometric relationship between VO2max and body mass ( y = a . x(b), where y is VO2max and x is body mass) was developed for 967 athle tes representing 25 different sports, with up to 157 participants in each s port. With an increasing number of observations, the exponent approached 0. 73, while for ventilation the exponent was only 0.55. By using the 0.73 exp onent for TO2max, the highest value [mean (SD)] for the males was obtained for the runners and cyclists [234 (16) ml . kg(-0.73) . min(-1)], and for t he females the highest value was found for the runners [189 (14) ml (.) kg( -0.73 .) min(-1)]. For the females, aerobic power was about 80% of the valu e achieved by the males. Scaling may help both in understanding variation i n aerobic power and in defining the physiological limitations of work capac ity.