Martin, Vanessa R.2011-07-222011-07-222006http://hdl.handle.net/10125/20667Thesis (M.S.)--University of Hawaii at Manoa, 2006.Includes bibliographical references (leaves 26-28).ix, 77 leaves, bound ill. 29 cmContext: Spectral analysis of beat-to-beat fluctuations in heart rate (Heart Rate Variability (HRV)) provides an efficient, non-invasive assessment of autonomic function and cardiovascular adaptations. Changes in HRV may result from a number of different physiological factors including training level and acclimation to altitude. Objective: To investigate the effects of intermittent hypoxic exposure (IHE) via CVACTM chamber on HRV in endurance trained athletes using autoregressive (AR) spectral analysis. Methods: Thirteen endurance trained subjects (four females; age 30.3 ± 8.9 years, nine males; age 30.1 ± 9.2 years) underwent an intermittent hypoxic conditioning protocol that involved increased exposure to altitude each week over eight weeks. Heart rate variability measures were taken in both supine and tilt positions pre and post altitude exposure to evaluate the acute effects, changes in acute effects over time, and chronic effects. Results: No significant differences were found in HRV using the AR spectral analysis (p>0.01). No negative effects of IHE on HRV were found. Conclusions: Intermittent hypoxic exposure delivered via CVACTM had no effect on HRV in endurance trained athletes when analyzed by the AR spectral analysis.en-USAll UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.Anoxemia -- Physiological effectAthletes -- Training ofThesis