Health, Exercise, and Sports Sciences ETDs

Publication Date

7-3-1969

Abstract

Eight healthy male subjects were administered maximal work tolerance tests on a motor driven treadmill while breathing a constant partial pressure of oxygen at 122 mmHg. Subjects were tested at three atmospheric pressures including 630 mmHg., 1520 mmHg., and 2280 mmHg. during a thirteen week period. Experimental tests were conducted in a compression chamber located in the Human Performance Laboratory at the University of New Mexico, Albuquerque, New Mexico. The hypotheses were that: 1) maximal oxygen uptake and maximal treadmill run time would be greater at 630 mmHg. than at 1520 mmHg. ambient pressure, 2) maximal oxygen uptake and maximal treadmill run time would be greater at 630 mmHg. than at 2280 mmHg. ambient pressure, and 3) maximal oxygen uptake and maximal treadmill run time would be greater at 1520 mmHg. than at 2280 mmHg. ambient pressure. The following measurements were made to assess maximal working tolerance and to assess respiratory and cardiovascular efficiency at the three experimental levels: 1) maximal oxygen uptake, 2) maximal treadmill run time, 3) maximal ventilation volume, 4) ventilation equivalent for oxygen, 5) mixed expired oxygen and carbon dioxide tensions, 6) maximal heart rate, and 7) terminal oxygen pulse. Mixed alveolar oxygen and carbon dioxide tensions were estimated using Bohr's equation with an assumed dead space to tidal volume ratio. Significant reductions in maximal working tolerance as indicated by maximal oxygen uptake and maximal treadmill run time were found at the one per cent level at 1520 mmHg. and 2280 mmHg. when compared with the mean data at 630 mmHg. ambient pressure. A significant reduction in maximal working tolerance was also found at the one per cent level at 2280 mmHg. when compared to the mean data at 1520 mmHg. ambient pressure. The reductions in maximal working tolerance at 1520 mmHg. and 2280 mmHg. ambient pressures were related to: 1) diminished ventilatory capacity due to increased respiratory flow resistance and increased work of breathing resulting in inadequate elimination of carbon dioxide and alveolar hypoxia and 2) the occurrence of nitrogen narcosis at 2280 mmHg. ambient pressure.

Document Type

Dissertation

Language

English

Degree Name

Physical Education, Sports and Exercise Science

Level of Degree

Doctoral

Department Name

Health, Exercise, and Sports Sciences

First Committee Member (Chair)

William Asmer Bynum Jr.

Second Committee Member

Marvin LeRoy Riedesel

Third Committee Member

Armond Harold Seidler

Fourth Committee Member

Wayne Paul Moellenberg

Fifth Committee Member

Ulrich Luft

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