PEAK OXYGEN DEFICIT DURING ONE-LEGGED AND 2-LEGGED CYCLING IN MEN ANDWOMEN

The objectives of this study were to determine the relationships of es timated active muscle mass and gender to anaerobic capacity, as measur ed 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 d etermined in young, physically active men (N = 11) and women (N = 9). For men and women, mean (+/-SD) peak oxygen deficit for one-legged cyc ling (2.27 +/- 0.30 and 1.18 +/- 0.18 l) was 52% of that for two-legge d cycling (4.40 +/-0.62 and 2.25 +/- 0.28 l). For all subjects and bot h modes of exercise, there was a strong linear relation between peak o xygen deficit (1) and estimated active muscle mass (FFLV) (r = 0.94). This relation was the same in one- and two-legged cycling, but was dif ferent for men and women. For a given FFLV, the peak oxygen deficit wa s,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 s tronger 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 acti ve muscle mass (FFLV), the peak oxygen deficit is higher in men than w omen; and (c) that the peak oxygen deficit is more strongly related th an VO2peak to the estimated quantity of active muscle.