Document Detail

Effect of various carbohydrate-electrolyte fluids on cycling performance and maximal voluntary contraction.
MedLine Citation:
PMID:  20479483     Owner:  NLM     Status:  MEDLINE    
The purpose of this study was to compare the effects of a carbohydrate-electrolyte plus caffeine, carnitine, taurine, and B vitamins solution (CE+) and a carbohydrate-electrolyte-only solution (CE) vs. a placebo solution (PLA) on cycling performance and maximal voluntary contraction (MVC). In a randomized, double-blind, crossover, repeated-measures design, 14 male cyclists (M +/- SD age 27 +/- 6 yr, VO2max 60.4 +/- 6.8 ml x kg-1 x min(-1)) cycled for 120 min submaximally (alternating 61% +/- 5% and 75% +/- 5% VO2max) and then completed a 15-min performance trial (PT). Participants ingested CE+, CE, or PLA before (6 ml/kg) and every 15 min during exercise (3 ml/kg). MVC was measured as a single-leg isometric extension (70 degree knee flexion) before (pre) and after (post) exercise. Rating of perceived exertion (RPE) was measured throughout. Total work accumulated (KJ) during PT was greater (p < .05) in CE+ (233 +/- 34) than PLA (205 +/- 52) but not in CE (225 +/- 39) vs. PLA. MVC (N) declined (p < .001) from pre to post in PLA (988 +/- 213 to 851 +/- 191) and CE (970 +/- 172 to 870 +/- 163) but not in CE+ (953 +/- 171 to 904 +/- 208). At Minutes 60, 90, 105, and 120 RPE was lower in CE+ (14 +/- 2, 14 +/- 2, 12 +/- 1, 15 +/- 2) than in PLA (14 +/- 2, 15 +/- 2, 14 +/- 2, 16 +/- 2; p < .001). CE+ resulted in greater total work than PLA. CE+, but not PLA or CE, attenuated pre-to-post MVC declines. Performance increases during CE+ may have been influenced by lower RPE and greater preservation of leg strength during exercise in part as a result of the hypothesized effects of CE+ on the central nervous system and skeletal muscle.
Matthew S Ganio; Jennifer F Klau; Elaine C Lee; Susan W Yeargin; Brendon P McDermott; Maxime Buyckx; Carl M Maresh; Lawrence E Armstrong
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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 Apr 
Date Detail:
Created Date:  2010-05-18     Completed Date:  2010-06-22     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:  104-14     Citation Subset:  IM    
Human Performance Laboratory, University of Connecticut, Storrs, CT, USA.
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MeSH Terms
Athletic Performance
Bicycling / physiology*
Caffeine / administration & dosage
Carnitine / administration & dosage
Cross-Over Studies
Dietary Carbohydrates / administration & dosage*,  pharmacology
Double-Blind Method
Electrolytes / administration & dosage*,  pharmacology
Isometric Contraction / drug effects,  physiology*
Muscle, Skeletal / physiology
Rehydration Solutions / administration & dosage*,  pharmacology
Task Performance and Analysis
Taurine / administration & dosage
Vitamin B Complex / adverse effects
Water-Electrolyte Balance / physiology
Reg. No./Substance:
0/Dietary Carbohydrates; 0/Electrolytes; 0/Rehydration Solutions; 107-35-7/Taurine; 12001-76-2/Vitamin B Complex; 541-15-1/Carnitine; 58-08-2/Caffeine

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

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