Document Detail

Effect of glycerol feeding on endurance and metabolism during prolonged exercise in man.
MedLine Citation:
PMID:  6353128     Owner:  NLM     Status:  MEDLINE    
This study evaluated the effectiveness of pre-exercise glycerol feeding in protecting against development of hypoglycemia and sparing muscle glycogen during prolonged, intense exercise. Thirty minutes after ingesting either glycerol (1 gm X kg-1 body weight) or a placebo, 10 cyclists performed as much exercise on a cycle ergometer as they were able in 150 min. The average exercise intensity was 72% of VO2max during both trials. Glycerol ingestion increased blood glycerol concentration 100-fold, but did not alter the respiratory exchange ratio (R), plasma levels of insulin and free-fatty acids, or blood lactate and beta-hydroxybutyrate. The only significant effect of glycerol feeding was to postpone the decline in blood glucose by about 30 min. This suggests that glycerol served, to a limited extent, as a gluconeogenic substrate; however, glycerol ingestion did not spare muscle glycogen during 90 min of treadmill exercise at 71% VO2max. It appears that man cannot utilize glycerol as gluconeogenic substrate rapidly enough to serve as a major energy source during strenuous exercise.
J M Miller; E F Coyle; W M Sherman; J M Hagberg; D L Costill; W J Fink; S E Terblanche; J O Holloszy
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Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  15     ISSN:  0195-9131     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  1983  
Date Detail:
Created Date:  1983-11-23     Completed Date:  1983-11-23     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  237-42     Citation Subset:  IM; S    
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MeSH Terms
Administration, Oral
Clinical Trials as Topic
Double-Blind Method
Exercise Test*
Glycerol / administration & dosage,  pharmacology*
Glycogen / metabolism*
Hypoglycemia / prevention & control
Muscles / metabolism*
Physical Endurance / drug effects*
Random Allocation
Sports Medicine*
Time Factors
Grant Support
Reg. No./Substance:
56-81-5/Glycerol; 9005-79-2/Glycogen

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

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