Document Detail


Failure of glycine-arginine-α-ketoisocaproic acid to improve high-intensity exercise performance in trained cyclists.
MedLine Citation:
PMID:  21411833     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Oral supplementation with glycine-arginine-α-ketoisocaproic acid (GAKIC) has previously been shown to improve exhaustive high-intensity exercise performance. There are no controlled studies involving GAKIC supplementation in well-trained subjects. The aim of the current study was to examine the effects of GAKIC supplementation on fatigue during high-intensity, repeated cycle sprints in trained cyclists. After at least 2 familiarization trials, 10 well-trained male cyclists completed 2 supramaximal sprint tests each involving 10 sprints of 10 s separated by 50-s rest intervals on an electrically braked cycle ergometer. Subjects ingested 11.2 g of GAKIC or placebo (Pl) during a period of 45 min before the 2 experimental trials, administered in a randomized and double-blind fashion. Peak power declined from the 1st sprint (M ± SD; Pl 1,332 ± 307 W, GAKIC 1,367 ± 342 W) to the 10th sprint (Pl 1,091 ± 229 W, GAKIC 1,061 ± 272 W) and did not differ between conditions (p = .88). Mean power declined from the 1st sprint (Pl 892 ± 151 W, GAKIC 892 ± 153 W) to the 10th sprint (Pl 766 ± 120 W, GAKIC 752 ± 138 W) and did not differ between conditions (p = .96). The fatigue index remained at ~38% throughout the series of sprints and did not differ between conditions (p = .99). Heart rate and ratings of perceived exertion increased from the 1st sprint to the 10th sprint and did not differ between conditions (p = .11 and p = .83, respectively). In contrast to previous studies in untrained individuals, these results suggest that GAKIC has no ergogenic effect on repeated bouts of high-intensity exercise in trained individuals.
Authors:
Lukas Beis; Yaser Mohammad; Chris Easton; Yannis P Pitsiladis
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Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  International journal of sport nutrition and exercise metabolism     Volume:  21     ISSN:  1526-484X     ISO Abbreviation:  Int J Sport Nutr Exerc Metab     Publication Date:  2011 Feb 
Date Detail:
Created Date:  2011-03-17     Completed Date:  2011-03-29     Revised Date:  2012-03-02    
Medline Journal Info:
Nlm Unique ID:  100939812     Medline TA:  Int J Sport Nutr Exerc Metab     Country:  United States    
Other Details:
Languages:  eng     Pagination:  33-9     Citation Subset:  IM    
Affiliation:
College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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MeSH Terms
Descriptor/Qualifier:
Adult
Athletic Performance / physiology*
Bicycling / physiology*
Dietary Supplements*
Double-Blind Method
Hexanoic Acids / administration & dosage,  pharmacology*
Humans
Male
Muscle Fatigue / drug effects
Physical Exertion / drug effects*
Chemical
Reg. No./Substance:
0/Hexanoic Acids; 0/glycine-L-arginine-alpha-ketoisocaproic acid

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


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