The aim of this study was to determine whether excessive oxygen uptake (V . o2) occurs not only during exercise but also during recovery after heavy exercise. After previous exercise at zero watts for 4 min, the main exercise was performed for 10 min. Then recovery exercise at zero watts was performed for 10 min. The main exercises were moderate and heavy exercises at exercise intensities of 40 % and 70 % of peak V . o2, respectively. V . o2 kinetics above zero watts was obtained by subtracting V . o2 at zero watts of previous exercise (?V . o2). ? V . o2 in moderate exercise was multiplied by the ratio of power output performed in moderate and heavy exercises so as to estimate the ? V . o2 applicable to heavy exercise. The difference between ? V . o2 in heavy exercise and ? V . o2 estimated from the value of moderate exercise was obtained. The obtained V . o2 was defined as excessive V . o2. The time constant of excessive V . o2 during exercise (1.88±0.70 min) was significantly shorter than that during recovery (9.61±6.92 min). Thus, there was excessive V . o2 during recovery from heavy exercise, suggesting that O2/ATP ratio becomes high after a time delay in heavy exercise and the high ratio continues until recovery.

Exercise Physiology Graduate School of Education Hokkaido University Kita ku Sapporo

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