Modeling maximum oxygen uptake of elite endurance athletes

Purpose: To compare the maximum oxygen uptake (VO2max) of elite endurance athletes and to explain why the body mass exponent, necessary to render VO2max independent of body mass, appears to be greater than 0.67.

Methods: Study 1: VO2max of 174 international sportsmen and women was assessed. Athletes were recruited from seven sports (middle- and long-distance runners, heavyweight and lightweight rowers, triathletes, and squash and badminton players). Study 2: calf and thigh leg muscle masses were estimated in 106 male and 30 female athletes from 11 sports. Differences in VO2max and leg muscle masses between “sports” and “sex” were analyzed independent of body mass by using allometric log-linear ANCOVA.

Results: Heavyweight rowers had the greatest VO2max when expressed in L.min^-1 but long-distance runners had the highest VO2max in mL.kg^-1.min^-1. However, the ANCOVA identified no difference in “mass independent”VO2max between the five “pure” endurance sports (runners, rowers, and triathletes) (P > 0.05) with the two racket sports being significantly lower. The body mass covariate exponent was inflated, estimated as 0.94. The results from study 2 estimated calf and thigh leg muscle masses to increase in proportion to body mass, m^1.11 and m^1.38, respectively.

Conclusions: After having controlled for differences in body mass,VO2max did not differ between pure endurance sports (P > 0.05). Assuming that athletes’ thigh muscle mass increases in proportion to body mass m^1.38 as observed in study 2, a similar disproportional increase in VO2max would be anticipated, providing a plausible explanation for the inflated mass exponent associated with V˙ O2max identified in this and other studies.