Abstract des Autors

The purpose of this investigation was to compare differences between one- and two-legged exercise on the lactate (LT) and ventilation (VT) threshold. On four separate occasions, eight male volunteer subjects (1-leg VO2max = 3.36 l/ min; 2-leg VO2max = 4.27 l/min) performed 1- and 2-legged submaximal and maximal exercise. Submaximal threshold tests for 1- and 2-legs, began with a warm-up at 50 W and then increased every 3 minutes by 16 W and 50 W, respectively. Similar increments occurred every minute for the maximal tests. Venous blood samples were collected during the last 30 s of each work load, whereas noninvasive gas measures were calculated every 30 s. No differences in VO2 (l/min) were found between 1- and 2-legs at LT or VT, but significant differences were recorded at a given power output. Lactate concentration ((LA)) was different between 1- and 2-legs (2.52 vs. 1.97 mmol/l) at LT. This suggests it is VO2 rather than muscle mass which affects LT and VT. VO2max for 1-leg exercise was 79 of the 2-leg value. This implies the central circulation rather than the peripheral muscle is limiting to VO2max.