Prior heavy exercise did not speed phase II VO2 kinetics, although it reduced the mean response time in a second heavy exercise bout (from 65.2 to 47.0 s; P<0.05) by reducing the slow component.
Does prior heavy exercise improve phase II pulmonary oxygen uptake kinetics during subsequent heavy exercise in human subjects?
Prior heavy exercise does not speed phase II pulmonary oxygen uptake kinetics during subsequent heavy exercise, with apparent speeding due instead to a reduction in the VO2 slow component.
p-value: p=<0.05
We tested the hypothesis that heavy-exercise phase II oxygen uptake (VO(2)) kinetics could be speeded by prior heavy exercise. Ten subjects performed four protocols involving 6-min exercise bouts on a cycle ergometer separated by 6 min of recovery: 1) moderate followed by moderate exercise; 2) moderate followed by heavy exercise; 3) heavy followed by moderate exercise; and 4) heavy followed by heavy exercise. The VO(2) responses were modeled using two (moderate exercise) or three (heavy exercise) independent exponential terms. Neither moderate- nor heavy-intensity exercise had an effect on the VO(2) kinetic response to subsequent moderate exercise. Although heavy-intensity exercise significantly reduced the mean response time in the second heavy exercise bout (from 65.2 +/- 4.1 to 47.0 +/- 3.1 s; P < 0.05), it had no significant effect on either the amplitude or the time constant (from 23.9 +/- 1.9 to 25.3 +/- 2.9 s) of the VO(2) response in phase II. Instead, this "speeding" was due to a significant reduction in the amplitude of the VO(2) slow component. These results suggest phase II VO(2) kinetics are not speeded by prior heavy exercise.
Burnley et al. (Sun,) reported a other. Prior heavy exercise vs. Prior moderate exercise was evaluated on Phase II pulmonary oxygen uptake (VO2) kinetics (p=<0.05). Prior heavy exercise did not speed phase II VO2 kinetics, although it reduced the mean response time in a second heavy exercise bout (from 65.2 to 47.0 s; P<0.05) by reducing the slow component.