Peak oxygen deficit during one- and two-legged cycling in men and women.

The objectives of this study were to determine the relationships of estimated active muscle mass and gender to anaerobic capacity, as measured by the peak oxygen deficit, and to compare these relationships with those for peak oxygen uptake (VO2peak). Fat-free leg volumes (FFLV), and one- and two-legged cycling peak oxygen deficit and VO2peak were determined in young, physically active men (N = 11) and women (N = 9). For men and women, mean (+/- SD) peak oxygen deficit for one-legged cycling (2.27 +/- 0.30 and 1.18 +/- 0.18 l) was 52% of that for two-legged cycling (4.40 +/- 0.62 and 2.25 +/- 0.28 l). For all subjects and both modes of exercise, there was a strong linear relation between peak oxygen deficit (1) and estimated active muscle mass (FFLV) (r = 0.94). This relation was the same in one- and two-legged cycling, but was different for men and women. For a given FFLV, the peak oxygen deficit was significantly higher (P < 0.05) in men than women by an average of 0.44 l. The relation of peak oxygen deficit to FFLV was significantly stronger than the relation of VO2peak to FFLV (r = 0.80). We conclude: (a) that the peak oxygen deficit is strongly related to the estimated active muscle mass during cycling; (b) that for a given estimated active muscle mass (FFLV), the peak oxygen deficit is higher in men than women; and (c) that the peak oxygen deficit is more strongly related than VO2peak to the estimated quantity of active muscle.