Abstract
We examined whether indirect maximal oxygen debt (YmA or YmB) derived by a mathematical equation (Dimri et al., 1980) would accurately approximate the directly measured maximal oxygen debt. The subjects for this study were 17 healthy male volunteers (8 athletes and 9 untrained college students) 18-26 years of age. An exhaustive 60-s cycling, as an exercise stimulus for determining maximal oxygen debt, was administered to each subject on a Monark bicycle ergometer with toe-stirrups. Criteria for the resting condition were a heart rate approximately equal to his usual rate and time of his lying (more than 30 min). The maximal oxygen debt (1) was calculated as the difference between the total oxygen uptake of recovery period (60 min) and the product of the pre-exercise resting oxygen uptake (1/min) and equivalent time in minutes required for the post-exercise gas collection. The pre- and post-exercise gas collection were made each minute during the respective entire testing periods. YmA and YmB were extrapolated from the measurements of excess oxygen uptake over the pre-exercise resting value at the end of 9 min and 15 min of the post-exercise period respectively ; and both were assumed to represent maximal oxygen debt over a 60 min period. YmA (6.73±2.60l) and YmB (6.24±2.10l) calculated from the extrapolation procedure were highly correlated (r=0.950 and r=0.940, respectively) with observed maximal oxygen debt. Absolute oxygen debt determined by the extrapolation procedure, however, differed siguificantly (P< 0.001) from the directly measured maximal oxygen debt (7.31±2.00l), i.e., YmA and YmB were 0.581 (or 7.9%) and 0.891 (12.2%) lower than the directly measured maximal oxygen debt. It is suggested that the extrapolation procedure proposed by Dimri et al. needs to be investigated in further studies.
