Annual Meeting Abstracts: H-20 – Free Communication/Poster: Hypoxia
PURPOSE: This study investigated the effect of exposure to short-term, intermittent hypobaric hypoxia (IHH) combined with sea-level training on running and swimming performance in well trained athletes. METHODS: 23 well-trained swimmers (13) and runners (10) were matched for gender, performance level and training history, and assigned to either hypobaric hypoxia (HYPO; simulated altitude of 4000–5500 m) or normoxia (NORM; 0–500 m) in a randomized, double blind, placebo controlled trial. Both groups rested in a hypobaric chamber for 3 h/day, 5 days a week, for 4 weeks. All subjects performed duplicate baseline time trials (3,000 m run, or 100 and 400 m swim), and maximal oxygen uptake tests on a treadmill and the swimming flume within three weeks before, and during the first and third week after the intervention. VO2 was measured by the Douglas bag method, with gas fractions being analyzed by mass spectrometry and ventilatory volumes using a Tissot spirometer. The best result of the baseline measurements was used for post test comparison using a 2-way RM ANOVA with main effects of test (Pre, Post 1, Post 2) and treatment (HYPO, NORM). RESULTS: No significant changes in time trial performance were observed for either the runners or swimmers, within or between groups. There was a main effect of test for VO2max (p = 0.02) and VEmax (p = 0.03). Post-hoc comparisons revealed an increase from Pre to Post 2 in VO2max (HYPO: +3.3%, p = 0.04; NORM: +0.9%, p = 0.10) and VEmax (p = 0.03; HYPO: +8.1%, p = <0.01; NORM: +1.2%, p = 0.64). No significant differences between groups were detected (group × test interaction, p = 0.3 and 0.1).
CONCLUSION: This protocol of exposure to intermittent hypobaric hypoxia (3 h/day, 5 days/wk, during 4 wks) did not improve swimming or running performance in this group of well-trained athletes. We could not detect a significant difference in the change of VO2max or VEmax between groups under the carefully controlled conditions of these experiments.
Supported by USOC, AIS, and ACSM (2003 International Scholar & Visiting Scholar Awards).