| Induced hypervolemia, cardiac function, VO2max, and performance of elite cyclists. | |
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MedLine Citation:
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PMID: 10378906 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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OBJECTIVE: To determine whether plasma volume expansion (PVexp) in elite endurance-trained (ET) cyclists, who already possess both a high blood volume (BV) and a high VO2max, leads to further enhancements in their cardiac function, VO2max, and endurance performance (time to exhaustion at 95% VO2max). METHODS: Nine male ET cyclists (V02max = 68.9 +/- 0.6 (SEM) mL x kg(-1) x min(-1)) were studied employing a double blind, cross-over design; i) before PVexp, ii) after sham PVexp (Sham), iii) after restoration of normocythemia, iv) after PVexp (6% dextran), and v) upon reestablishment of normocythemia. RESULTS: PVexp resulted in a 547 +/- 61 mL increase in BV (P < 0.05). Maximal cardiac output and maximal stroke volume were higher (P < 0.05) after PVexp, but the magnitude of these increases was only sufficient to counter the hemodilution effect (lowered O2 content) of PVexp, such that O2 transport, VO2max, and endurance performance remained unchanged. CONCLUSIONS: Expansion of BV in elite ET cyclists, who already possess a high BV, does not improve their VO2max and endurance performance. Elite ET athletes may already be at an optimal BV, which is at or near the limits of their diastolic reserve capacity. |
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Authors:
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D E Warburton; N Gledhill; V K Jamnik; B Krip; N Card |
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Publication Detail:
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Type: Clinical Trial; Controlled Clinical Trial; Journal Article |
Journal Detail:
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Title: Medicine and science in sports and exercise Volume: 31 ISSN: 0195-9131 ISO Abbreviation: Med Sci Sports Exerc Publication Date: 1999 Jun |
Date Detail:
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Created Date: 1999-08-30 Completed Date: 1999-08-30 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 8005433 Medline TA: Med Sci Sports Exerc Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 800-8 Citation Subset: IM; S |
Affiliation:
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Kinesiology and Health Science, York University, North York, Ontario, Canada. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Bicycling / physiology* Blood Volume / physiology* Cardiac Output / physiology* Cardiovascular Physiological Phenomena Humans Male Oxygen Consumption / physiology* Physical Endurance / physiology* Stroke Volume |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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