Document Detail


Beta-alanine supplementation reduces acidosis but not oxygen uptake response during high-intensity cycling exercise.
MedLine Citation:
PMID:  19841932     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The oral ingestion of beta-alanine, the rate-limiting precursor in carnosine synthesis, has been shown to elevate the muscle carnosine content. Carnosine is thought to act as a physiologically relevant pH buffer during exercise but direct evidence is lacking. Acidosis has been hypothesised to influence oxygen uptake kinetics during high-intensity exercise. The present study aimed to investigate whether oral beta-alanine supplementation could reduce acidosis during high-intensity cycling and thereby affect oxygen uptake kinetics. 14 male physical education students participated in this placebo-controlled, double-blind study. Subjects were supplemented orally for 4 weeks with 4.8 g/day placebo or beta-alanine. Before and after supplementation, subjects performed a 6-min cycling exercise bout at an intensity of 50% of the difference between ventilatory threshold (VT) and VO(2peak). Capillary blood samples were taken for determination of pH, lactate, bicarbonate and base excess, and pulmonary oxygen uptake kinetics were determined with a bi-exponential model fitted to the averaged breath-by-breath data of three repetitions. Exercise-induced acidosis was significantly reduced following beta-alanine supplementation compared to placebo, without affecting blood lactate and bicarbonate concentrations. The time delay of the fast component (Td(1)) of the oxygen uptake kinetics was significantly reduced following beta-alanine supplementation compared to placebo, although this did not reduce oxygen deficit. The parameters of the slow component did not differ between groups. These results indicate that chronic beta-alanine supplementation, which presumably increased muscle carnosine content, can attenuate the fall in blood pH during high-intensity exercise. This may contribute to the ergogenic effect of the supplement found in some exercise modes.
Authors:
Audrey Baguet; Katrien Koppo; Andries Pottier; Wim Derave
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't     Date:  2009-10-16
Journal Detail:
Title:  European journal of applied physiology     Volume:  108     ISSN:  1439-6327     ISO Abbreviation:  Eur. J. Appl. Physiol.     Publication Date:  2010 Feb 
Date Detail:
Created Date:  2010-01-20     Completed Date:  2010-04-08     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100954790     Medline TA:  Eur J Appl Physiol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  495-503     Citation Subset:  IM    
Affiliation:
Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium.
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MeSH Terms
Descriptor/Qualifier:
Acidosis / metabolism,  physiopathology,  prevention & control*
Adult
Blood Gas Analysis
Dietary Supplements
Dose-Response Relationship, Drug
Double-Blind Method
Exercise / physiology*
Exercise Test
Humans
Male
Muscle, Skeletal / metabolism
Oxygen Consumption / drug effects*,  physiology
Pulmonary Gas Exchange / physiology
Time Factors
beta-Alanine / administration & dosage,  pharmacology*
Chemical
Reg. No./Substance:
107-95-9/beta-Alanine

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


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