Document Detail


Increased blood pH but not performance with sodium bicarbonate supplementation in elite rugby union players.
MedLine Citation:
PMID:  20739719     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: This study investigated the effect of ingesting 0.3 g/kg body weight (BW) of sodium bicarbonate (NaHCO₃) on physiological responses, gastrointestinal (GI) tolerability, and sprint performance in elite rugby union players. METHODS: Twenty-five male rugby players, age 21.6 (2.6) yr, participated in a randomized, double-blind, placebo-controlled crossover trial. Sixty-five minutes after consuming 0.3 g/kg BW of either NaHCO₃ or placebo, participants completed a 25-min warm-up followed by 9 min of high-intensity rugby-specific training followed by a rugby-specific repeated-sprint test (RSRST). Whole-blood samples were collected to determine lactate and bicarbonate concentrations and pH at baseline, after supplement ingestion, and immediately after the RSRST. Acute GI discomfort was assessed by questionnaire throughout the trials, and chronic GI discomfort was assessed during the 24 hr postingestion. RESULTS: After supplement ingestion and immediately after the RSRST, blood HCO₃⁻ concentration and pH were higher for the NaHCO₃ condition than for the placebo condition (p < .001). After the RSRST, blood lactate concentrations were significantly higher for the NaHCO₃ than for the placebo condition (p < .001). There was no difference in performance on the RSRST between the 2 conditions. The incidence of belching, stomachache, diarrhea, stomach bloating, and nausea was higher after ingestion of NaHCO₃ than with placebo (all p < .050). The severity of stomach cramps, belching, stomachache, bowel urgency, diarrhea, vomiting, stomach bloating, and flatulence was rated worse after ingestion of NaHCO₃ than with placebo (p < .050). CONCLUSIONS: NaHCO₃ supplementation increased blood HCO₃⁻ concentration and attenuated the decline in blood pH compared with placebo during high-intensity exercise in well-trained rugby players but did not significantly improve exercise performance. The higher incidence and greater severity of GI symptoms after ingestion of NaHCO₃ may negatively affect physical performance, and the authors strongly recommend testing this supplement during training before use in competitive situations.
Authors:
Sonya L Cameron; Rebecca T McLay-Cooke; Rachel C Brown; Andrew R Gray; Kirsty A Fairbairn
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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:  20     ISSN:  1526-484X     ISO Abbreviation:  Int J Sport Nutr Exerc Metab     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-08-26     Completed Date:  2010-11-02     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100939812     Medline TA:  Int J Sport Nutr Exerc Metab     Country:  United States    
Other Details:
Languages:  eng     Pagination:  307-21     Citation Subset:  IM    
Affiliation:
Dept. of Human Nutrition, University of Otago, Dunedin, New Zealand.
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MeSH Terms
Descriptor/Qualifier:
Acid-Base Equilibrium / drug effects*,  physiology
Athletic Performance / physiology*
Bicarbonates / blood*
Cross-Over Studies
Dietary Supplements
Double-Blind Method
Football / physiology*
Gastrointestinal Diseases / chemically induced
Humans
Hydrogen-Ion Concentration / drug effects
Lactic Acid / blood
Male
Oxygen Consumption / physiology
Running / physiology
Sodium Bicarbonate / administration & dosage*,  adverse effects
Young Adult
Chemical
Reg. No./Substance:
0/Bicarbonates; 144-55-8/Sodium Bicarbonate; 50-21-5/Lactic Acid

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


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