The effect of intermittent hypobaric hypoxic exposure and sea level training on submaximal economy in well-trained swimmers and runners.
To evaluate the effect of intermittent hypobaric hypoxia combined with sea level training on exercise economy, 23 well-trained athletes (13 swimmers, 10 runners) were assigned to either hypobaric hypoxia (simulated altitude of 4,000-5,500 m) or normobaric normoxia (0-500 m) in a randomized, double-blind design. Both groups rested in a hypobaric chamber 3 h/day, 5 days/wk for 4 wk. Submaximal economy was measured twice before (Pre) and after (Post) the treatment period using sport-specific protocols. Economy was estimated both from the relationship between oxygen uptake (V(.-)o2) and speed, and from the absolute V(.-)o2 at each speed using sport-specific protocols. V(.-)o2 was measured during the last 60 s of each (3-4 min) stage using Douglas bags. Ventilation (V(.-)E), heart rate (HR), and capillary lactate concentration ([La(-)]) were measured during each stage. Velocity at maximal V(.-)o2 (velocity at V(.-)o2max) was used as a functional indicator of changes in economy. The average V(.-)o2 for a given speed of the Pre values was used for Post test comparison using a two-way, repeated-measures ANOVA. Typical error of measurement of V(.-)o2 was 4.7% (95% confidence limits 3.6-7.1), 3.6% (2.8-5.4), and 4.2% (3.2-6.9) for speeds 1, 2, and 3, respectively. There was no change in economy within or between groups (ANOVA interaction P = 0.28, P = 0.23, and P = 0.93 for speeds 1, 2, and 3). No differences in submaximal HR, [La-], Ve, or velocity at V(.-)o2(max) were found between groups. It is concluded that 4 wk of intermittent hypobaric hypoxia did not improve submaximal economy in this group of well-trained athletes.
Faculty of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Martin J
MJ
Truijens
Ferran A
FA
Rodríguez
Nathan E
NE
Townsend
James
J
Stray-Gundersen
Christopher J
CJ
Gore
Benjamin D
BD
Levine
D000064:Acclimatization; D000328:Adult; D000531:Altitude; D004311:Double-Blind Method; D015444:Exercise; D005260:Female; D006339:Heart Rate; D006801:Humans; D000860:Hypoxia / Q000378:metabolism / Q000503:physiopathology*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D016555:Matched-Pair Analysis; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology*; D010101:Oxygen Consumption; D012123:Pulmonary Ventilation; D015203:Reproducibility of Results; D012420:Running; D013550:Swimming; D013997:Time Factors
D019344:Lactic Acid