15623
document
Effect of a carbohydrate-protein supplement on endurance performance during exercise of varying intensity . Increasing the plasma glucose and insulin concentrations during prolonged variable intensity exercise by supplementing with carbohydrate has been found to spare muscle glycogen and increase aerobic endurance . Furthermore , the addition of protein to a carbohydrate supplement will enhance the insulin response of a carbohydrate supplement . The purpose of the present study was to compare the effects of a carbohydrate and a carbohydrate-protein supplement on aerobic endurance performance . Nine trained cyclists exercised on 3 separate occasions at intensities that varied between 45 % and 75 % VO2max for 3 h and then at 85 % VO2max until fatigued . Supplements ( 200 ml ) were provided every 20 min and consisted of placebo , a 7.75 % carbohydrate solution , and a 7.75 % carbohydrate/1.94 % protein solution . Treatments were administered using a double-blind randomized design . Carbohydrate supplementation significantly increased time to exhaustion ( carbohydrate 19.7 +/- 4.6 min vs. placebo 12.7 +/- 3.1 min ) , while the addition of protein enhanced the effect of the carbohydrate supplement ( carbohydrate-protein 26.9 +/- 4.5 min , p < .05 ) . Blood glucose and plasma insulin levels were elevated above placebo during carbohydrate and carbohydrate-protein supplementation , but no differences were found between the carbohydrate and carbohydrate-protein treatments . In summary , we found that the addition of protein to a carbohydrate supplement enhanced aerobic endurance performance above that which occurred with carbohydrate alone , but the reason for this improvement in performance was not evident .
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Intervention_Pharmacological
carbohydrate-protein supplement
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Intervention_Pharmacological
protein to a carbohydrate supplement
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Intervention_Pharmacological
carbohydrate
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Intervention_Pharmacological
carbohydrate-protein supplement
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Intervention_Control
placebo
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Intervention_Pharmacological
carbohydrate solution
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Intervention_Pharmacological
carbohydrate/1.94
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Intervention_Pharmacological
protein solution
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Intervention_Pharmacological
carbohydrate
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Intervention_Pharmacological
carbohydrate-protein supplementation
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Intervention_Pharmacological
carbohydrate-protein
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Intervention_Pharmacological
carbohydrate supplement
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Outcome_Physical
endurance performance
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Outcome_Physical
aerobic endurance
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Outcome_Physical
aerobic endurance performance
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Outcome_Physical
time to exhaustion
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Outcome_Physical
Blood glucose and plasma insulin levels
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Outcome_Physical
aerobic endurance performance
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Participant_Condition
Nine trained cyclists