Workman, Chad (2013) Effects of intermittent normobaric hypoxia on substrate utilization and metabolic rate in sedentary males. Masters thesis, Memorial University of Newfoundland.
- Accepted Version
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The purpose of this study was to determine the effects of intermittent normobaric hypoxia on resting metabolic rate and substrate preference in sedentary males. After a 12-hour fast, 11 sedentary male subjects (acute) were individually exposed to 3 hours of intermittent normobaric hypoxia, achieving an isometabolic stress of ~80% oxygen saturation. A subset of 6 subjects (short term) continued with the hypoxia exposure for a further 6 sessions. Resting metabolic data was acquired immediately before and after the hypoxic exposure on day 1 for the acute exposure group and on days 1 and 7 for the short-term exposure group. Heart rate, blood pressure, oxygen saturation and Acute Mountain Sickness Score were monitored and recorded. In the acute exposure group, there was a significant increase in oxygen consumption, from 315 ml·min (±10) to 371 ml·min (±10). As well, there was a significant reduction of the respiratory exchange ratio, from 0.89 (±0.1) to 0.76 (±0.06). There was also a significant increase in oxygen consumption in the short-term exposure group, from 322 ml·min (±10) on pre-exposure day 1, to 3 7 6 ml·min (±7) post exposure on day 7 and a significant reduction in respiratory exchange ratio from 0.86 (±0.09) on preexposure day 1 to 0.73 (±0.05) post exposure day 7. These results demonstrate that intermittent normobaric hypoxia, as described here, is sufficient to induce an increase in resting metabolic rate resulting in a switch from primarily carbohydrate to primarily lipid substrate as the main energy source.
|Item Type:||Thesis (Masters)|
|Additional Information:||Includes bibliographical references (leaves 110-117).|
|Department(s):||Human Kinetics and Recreation, School of|
|Library of Congress Subject Heading:||Sedentary people; Exercise for men--Physiological aspects; Exercise tests; Oxygen--Metabolism.|
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