| ATP production and efficiency of human skeletal muscle during intense exercise: effect of previous exercise. | |
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MedLine Citation:
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PMID: 11350777 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The aim of the present study was to examine whether ATP production increases and mechanical efficiency decreases during intense exercise and to evaluate how previous exercise affects ATP turnover during intense exercise. Six subjects performed two (EX1 and EX2) 3-min one-legged knee-extensor exercise bouts [66.2 +/- 3.9 and 66.1 +/- 3.9 (+/-SE) W] separated by a 6-min rest period. Anaerobic ATP production, estimated from net changes in and release of metabolites from the active muscle, was 3.5 +/- 1.2, 2.4 +/- 0.6, and 1.4 +/- 0.2 mmol ATP x kg dry wt(-1) x s(-1) during the first 5, next 10, and remaining 165 s of EX1, respectively. The corresponding aerobic ATP production, determined from muscle oxygen uptake, was 0.7 +/- 0.1, 1.4 +/- 0.2, and 4.7 +/- 0.4 mmol ATP x kg dry wt(-1) x s(-1), respectively. The mean rate of ATP production during the first 5 s and next 10 s was lower (P < 0.05) than during the rest of the exercise (4.2 +/- 1.2 and 3.8 +/- 0.7 vs. 6.1 +/- 0.3 mmol ATP x kg dry wt(-1) x s(-1)). Thus mechanical efficiency, expressed as work per ATP produced, was lowered (P < 0.05) in the last phase of exercise (39.6 +/- 6.1 and 40.7 +/- 5.8 vs. 25.0 +/- 1.3 J/mmol ATP). The anaerobic ATP production was lower (P < 0.05) in EX2 than in EX1, but the aerobic ATP turnover was higher (P < 0.05) in EX2 than in EX1, resulting in the same muscle ATP production in EX1 and EX2. The present data suggest that the rate of ATP turnover increases during intense exercise at a constant work rate. Thus mechanical efficiency declines as intense exercise is continued. Furthermore, when intense exercise is repeated, there is a shift toward greater aerobic energy contribution, but the total ATP turnover is not significantly altered. |
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Authors:
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J Bangsbo; P Krustrup; J González-Alonso; B Saltin |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: American journal of physiology. Endocrinology and metabolism Volume: 280 ISSN: 0193-1849 ISO Abbreviation: Am. J. Physiol. Endocrinol. Metab. Publication Date: 2001 Jun |
Date Detail:
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Created Date: 2001-05-14 Completed Date: 2001-06-14 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 100901226 Medline TA: Am J Physiol Endocrinol Metab Country: United States |
Other Details:
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Languages: eng Pagination: E956-64 Citation Subset: IM |
Affiliation:
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Copenhagen Muscle Research Centre, The August Krogh Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark. jbangsbo@aki.ku.dk |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adenosine Triphosphate
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biosynthesis*,
metabolism Adult Anaerobic Threshold / physiology Exercise / physiology Humans Lactic Acid / metabolism Leg / blood supply Male Muscle, Skeletal / blood supply, metabolism* Phosphocreatine / metabolism Physical Exertion / physiology* Regional Blood Flow / physiology |
| Chemical | |
Reg. No./Substance:
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50-21-5/Lactic Acid; 56-65-5/Adenosine Triphosphate; 67-07-2/Phosphocreatine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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