Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1986-9-17
pubmed:abstractText
The purpose of this study was to determine whether the postponement of fatigue in subjects fed carbohydrate during prolonged strenuous exercise is associated with a slowing of muscle glycogen depletion. Seven endurance-trained cyclists exercised at 71 +/- 1% of maximal O2 consumption (VO2max), to fatigue, while ingesting a flavored water solution (i.e., placebo) during one trial and while ingesting a glucose polymer solution (i.e., 2.0 g/kg at 20 min and 0.4 g/kg every 20 min thereafter) during another trial. Fatigue during the placebo trial occurred after 3.02 +/- 0.19 h of exercise and was preceded by a decline (P less than 0.01) in plasma glucose to 2.5 +/- 0.5 mM and by a decline in the respiratory exchange ratio (i.e., R; from 0.85 to 0.80; P less than 0.05). Glycogen within the vastus lateralis muscle declined at an average rate of 51.5 +/- 5.4 mmol glucosyl units (GU) X kg-1 X h-1 during the first 2 h of exercise and at a slower rate (P less than 0.01) of 23.0 +/- 14.3 mmol GU X kg-1 X h-1 during the third and final hour. When fed carbohydrate, which maintained plasma glucose concentration (4.2-5.2 mM), the subjects exercised for an additional hour before fatiguing (4.02 +/- 0.33 h; P less than 0.01) and maintained their initial R (i.e., 0.86) and rate of carbohydrate oxidation throughout exercise. The pattern of muscle glycogen utilization, however, was not different during the first 3 h of exercise with the placebo or the carbohydrate feedings. The additional hour of exercise performed when fed carbohydrate was accomplished with little reliance on muscle glycogen (i.e., 5 mmol GU X kg-1 X h-1; NS) and without compromising carbohydrate oxidation. We conclude that when they are fed carbohydrate, highly trained endurance athletes are capable of oxidizing carbohydrate at relatively high rates from sources other than muscle glycogen during the latter stages of prolonged strenuous exercise and that this postpones fatigue.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
61
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
165-72
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:3525502-Adult, pubmed-meshheading:3525502-Blood Glucose, pubmed-meshheading:3525502-Capillaries, pubmed-meshheading:3525502-Dietary Carbohydrates, pubmed-meshheading:3525502-Fatty Acids, Nonesterified, pubmed-meshheading:3525502-Glycerol, pubmed-meshheading:3525502-Glycogen, pubmed-meshheading:3525502-Heart Rate, pubmed-meshheading:3525502-Humans, pubmed-meshheading:3525502-Insulin, pubmed-meshheading:3525502-Lactates, pubmed-meshheading:3525502-Male, pubmed-meshheading:3525502-Muscles, pubmed-meshheading:3525502-Osmolar Concentration, pubmed-meshheading:3525502-Oxygen Consumption, pubmed-meshheading:3525502-Physical Endurance, pubmed-meshheading:3525502-Physical Exertion, pubmed-meshheading:3525502-Pulmonary Gas Exchange, pubmed-meshheading:3525502-Self Concept, pubmed-meshheading:3525502-Time Factors
pubmed:year
1986
pubmed:articleTitle
Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't