Abstract des Autors

Ten healthy subjects have volunteered to take part in two incremental cycle exercises. The subjects performed tests under two different conditions. 1) Condition M: Use a metronome to maintain pedalling frequency so entrainment would easily occur. 2) Condition S: Use a tachometer to maintain pedalling frequency so entrainment would not easily occur. Oxygen uptake (VO2) at AT was determined by two different methods. The first method was to detect the point of non-linear increase in minute ventilation (VE) and carbon dioxide output (VCO2) and then to increase detection in the ventilatory equivalent for O2 (VE/VO2) without increasing the ventilatory equivalent for CO2 (VE/VCO2) (AT-V). The second method was to detect inflection in f by multisegment linear regression (AT-CF). There were no significant differences between AT-V (condition M: 26.0 +/- 6.2, condition S: 26.4 +/- 6.0 ml/kg/min) and AT-DV (condition M: 31.6 +/- 10.2, condition S: 24.7 +/- 10.0 ml/kg/min). A significant positive correlation between AT-V and AT-CF was observed in condition S (R = 0.850, p < 0.05), but not in condition M (r = 0.563, p > 0.05). The error between AT-V and AT-CF had individual variations. An error within +/-5% was observed in only 4 out of 10 subjects. These results suggested that even though the ability to detect AT using f is superior in condition S, f is an inadequate indicator for the AT, though the exercise entrained breathing is minimized. Verf.-Referat