| The relationship between the VO2 slow component, muscle metabolites and performance during very-heavy exhaustive exercise. | |
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MedLine Citation:
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PMID: 16890488 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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This study examined the relationship between the V O(2) response, particularly the slow component (SC), muscle metabolite changes and performance during very-heavy exhaustive exercise. Sixteen active females performed a graded exercise test to determine V O(2peak) and the lactate threshold followed 48h later by a constant-load cycle test to exhaustion (ET) at 85% V O(2peak) intensity. Muscle biopsies and capillary blood samples were obtained before and after the ET to determine changes in muscle ATP, pH, lactate and phosphocreatine and also plasma pH and lactate. Breath-by-breath data from the ET were smoothed using 5-s averages and fit to a three-component exponential model. The mean time to exhaustion (t(exh)) during the ET was 16.8 (+/-6.4) min. Results showed no correlation between the SC and t(exh) or any muscle metabolite changes (p>0.05). Significant correlations (p<0.05) were evident between t(exh) and tau; tau(0) (r=-0.54), tau(1) (r=-0.65), change in (Delta) pH(b) (r=-0.60), Delta[La(-)](b) (r=-0.58) and [La(-)](b post) (r=-0.64). Significant correlations (p<0.05) were also evident between tau(1) and [La(-)](b post) (r=0.54). Furthermore, a negative value resulted when the accumulated oxygen deficit was calculated for the entire duration of the ET. Results showed no association between the amplitude of the SC and t(ext) or to changes in muscle/blood metabolites, suggesting that the SC is not a determinant of high-intensity exercise tolerance. Furthermore, it is possible that a reduced perturbation of anaerobic energy sources, as a result of a faster tau(1), may have contributed to a longer t(exh). |
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Authors:
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Rob Duffield; Johann Edge; David Bishop; Carmel Goodman |
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Publication Detail:
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Type: Journal Article Date: 2006-08-04 |
Journal Detail:
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Title: Journal of science and medicine in sport / Sports Medicine Australia Volume: 10 ISSN: 1440-2440 ISO Abbreviation: J Sci Med Sport Publication Date: 2007 Jun |
Date Detail:
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Created Date: 2007-04-20 Completed Date: 2007-10-15 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 9812598 Medline TA: J Sci Med Sport Country: Australia |
Other Details:
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Languages: eng Pagination: 127-34 Citation Subset: IM |
Affiliation:
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School of Human Movement and Exercise Science, The University of Western Australia, Crawley WA, Australia. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adenosine Triphosphate
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analysis Adolescent Adult Analysis of Variance Creatinine / analysis Exercise / physiology* Exercise Test Female Humans Lactic Acid / analysis Muscle Fatigue / physiology Muscle, Skeletal / metabolism* Oxygen Consumption / physiology Phosphocreatine / analogs & derivatives, analysis Physical Endurance / physiology* Physical Exertion / physiology* |
| Chemical | |
Reg. No./Substance:
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50-21-5/Lactic Acid; 56-65-5/Adenosine Triphosphate; 5786-71-0/phosphocreatinine; 60-27-5/Creatinine; 67-07-2/Phosphocreatine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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