Document Detail

Cycling performance following adaptation to two protocols of acutely intermittent hypoxia.
MedLine Citation:
PMID:  19417229     Owner:  NLM     Status:  MEDLINE    
PURPOSE: Adaptation to acutely intermittent hypoxic exposure appears to produce worthwhile enhancements in endurance performance, but the current 5-min duration of hypoxia and recovery intervals may not be optimal. METHODS: Eighteen male competitive cyclists and triathletes were randomized to one of two intermittent-hypoxia groups, and nine similar athletes represented a control group. Athletes in the hypoxia groups were exposed to 60 min per day of intermittent hypoxia consisting of alternating intervals of hypoxia and normoxia lasting either 3 or 5 min. Exposures were performed at rest for 5 consecutive days per week for 3 wk. Oxygen saturation, monitored with pulse oximetry, was reduced progressively from 90% (day 1) to 76% (day 15). All athletes maintained their usual competitive-season training throughout the study. Incremental and repeated-sprint tests were performed pre, 3 d post, and 14 d postintervention. Venous blood at rest was sampled pre, mid-, and postintervention. RESULTS: There were no clear differences between effects of the two hypoxic treatments on performance or various measures of oxygen transport, hematopoiesis, and inflammation. Compared with control, the combined hypoxic groups showed clear enhancements in peak power (4.7%; 90% confidence limits, +/-3.1%), lactate-profile power (4.4%; +/-3.0%), and heart-rate profile power (6.5%; +/-5.3%) at 3 d postintervention, but at 14 d the effects were unclear. Changes in other measures at 3 and 14 d postintervention were either unclear or unremarkable. CONCLUSION: Acutely intermittent hypoxia produced substantial enhancement in endurance performance, but the relative benefit of 3- vs 5-min exposure intervals remains unclear.
Darrell L Bonetti; Will G Hopkins; Timothy E Lowe; Alain Boussana; Andrew E Kilding
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Publication Detail:
Type:  Journal Article; Randomized Controlled Trial    
Journal Detail:
Title:  International journal of sports physiology and performance     Volume:  4     ISSN:  1555-0265     ISO Abbreviation:  -     Publication Date:  2009 Mar 
Date Detail:
Created Date:  2009-05-06     Completed Date:  2009-10-20     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101276430     Medline TA:  Int J Sports Physiol Perform     Country:  United States    
Other Details:
Languages:  eng     Pagination:  68-83     Citation Subset:  IM    
Institute of Sport and Recreation Research, New Zealand School of Sort and Recreation, AUT University, Auckland, NZ.
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MeSH Terms
Adaptation, Physiological / physiology*
Anoxia / physiopathology*
Bicycling / physiology*
Confidence Intervals
Exercise Test
Heart Rate
Inflammation / physiopathology
Lactic Acid / blood
Oxygen Consumption
Task Performance and Analysis
Time Factors
Reg. No./Substance:
50-21-5/Lactic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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