Document Detail


Anaerobic energy expenditure and mechanical efficiency during exhaustive leg press exercise.
MedLine Citation:
PMID:  20976067     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Information about anaerobic energy production and mechanical efficiency that occurs over time during short-lasting maximal exercise is scarce and controversial. Bilateral leg press is an interesting muscle contraction model to estimate anaerobic energy production and mechanical efficiency during maximal exercise because it largely differs from the models used until now. This study examined the changes in muscle metabolite concentration and power output production during the first and the second half of a set of 10 repetitions to failure (10RM) of bilateral leg press exercise. On two separate days, muscle biopsies were obtained from vastus lateralis prior and immediately after a set of 5 or a set of 10 repetitions. During the second set of 5 repetitions, mean power production decreased by 19% and the average ATP utilisation accounted for by phosphagen decreased from 54% to 19%, whereas ATP utilisation from anaerobic glycolysis increased from 46 to 81%. Changes in contraction time and power output were correlated to the changes in muscle Phosphocreatine (PCr; r = -0.76; P<0.01) and lactate (r = -0.91; P<0.01), respectively, and were accompanied by parallel decreases (P<0.01-0.05) in muscle energy charge (0.6%), muscle ATP/ADP (8%) and ATP/AMP (19%) ratios, as well as by increases in ADP content (7%). The estimated average rate of ATP utilisation from anaerobic sources during the final 5 repetitions fell to 83% whereas total anaerobic ATP production increased by 9% due to a 30% longer average duration of exercise (18.4 ± 4.0 vs 14.2 ± 2.1 s). These data indicate that during a set of 10RM of bilateral leg press exercise there is a decrease in power output which is associated with a decrease in the contribution of PCr and/or an increase in muscle lactate. The higher energy cost per repetition during the second 5 repetitions is suggestive of decreased mechanical efficiency.
Authors:
Esteban M Gorostiaga; Ion Navarro-Amézqueta; Roser Cusso; Ylva Hellsten; Jose A L Calbet; Mario Guerrero; Cristina Granados; Miriam González-Izal; Javier Ibáñez; Mikel Izquierdo
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-10-19
Journal Detail:
Title:  PloS one     Volume:  5     ISSN:  1932-6203     ISO Abbreviation:  PLoS ONE     Publication Date:  2010  
Date Detail:
Created Date:  2010-10-26     Completed Date:  2011-03-07     Revised Date:  2013-07-03    
Medline Journal Info:
Nlm Unique ID:  101285081     Medline TA:  PLoS One     Country:  United States    
Other Details:
Languages:  eng     Pagination:  e13486     Citation Subset:  IM    
Affiliation:
Studies, Research and Sport Medicine Center, Government of Navarre, Navarre, Spain.
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MeSH Terms
Descriptor/Qualifier:
Adenosine Diphosphate / metabolism
Adenosine Monophosphate / metabolism
Adenosine Triphosphate / metabolism
Anaerobiosis
Energy Metabolism*
Humans
Male
Weight Lifting*
Chemical
Reg. No./Substance:
56-65-5/Adenosine Triphosphate; 58-64-0/Adenosine Diphosphate; 61-19-8/Adenosine Monophosphate
Comments/Corrections

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