The effect of exercise intensity on VO2 drift in persons of different fitness levels /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1993.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | The purpose of this study was to evaluate oxygen consumption (VO2) drift in persons of different fitness levels exercising at different relative intensities. In addition, the contribution of proposed mediators of VO2 drift was estimated using equations from the literature. Low (n=15) and high (n=15) fitness (M VO2 max of 37 vs 62 mL*min^-1*kg^-1) males were recruited. Each subject completed, in random order, a series of 12 min stationary bicycle ergometer exercise trials corresponding to 50, 60, 70 and 80% of VO2 max. VO2, minute ventilation, blood lactate, rectal temperature, heart rate and blood pressure were measured throughout each trial. A three factor (fitness, workload, time) repeated measures MANOVA found significant interactions. Subsequent follow up procedures indicated that there was a significant VO2 drift for each level of fitness across time and at each workload. There were no differences between the fitness levels for VO2 drift or any of the proposed mediators. The VO2 drift ranged from 70 mL*min^-1 for the lighter workloads to 543 mL1*min^-1 for the high fitness group at 80% of maximal VO2. The oxygen cost of the proposed mediators was estimated from equations in the literature. The oxygen cost of minute ventilation, body temperature and rate pressure product accounted for about 50% of the observed VO2 drift. Of these, minute ventilation appears to increase in a pattern most similar to the VO2 drift and the oxygen cost of minute ventilation generally accounted for the highest percentage of the observed V02 drift. These results suggest that minute ventilation appears to be the primary mediator of VO2 drift. However, the contribution of body temperature, blood lactate and work of the heart can not be neglected. It also seems apparent that other mediators such as catecholamines need to be considered. |
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| Item Description: | Vita. "Major subject: Kinesiology." Numeral 2 in title is subscript. |
| Physical Description: | xii, 101 leaves : illustrations ; 28 cm |
| Bibliography: | Includes bibliographical references. |