Effect of carbohydrate or carbohydrate plus medium-chain triglyceride ingestion on cycling time trial performance

Damien J. Angus, Mark Hargreaves, Jane Dancey, Mark A. Febbraio

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72 Citations (Scopus)

Abstract

This study examined the effectiveness of ingesting a carbohydrate or carbohydrate + medium-chain triglycerides (MCT) on metabolism and cycling performance. Eight endurance-trained men [peak O2 uptake = 4.71 ± 0.09 (SE) l/min] completed 35 kJ/kg as quickly as possible [time trial (TT)] while consuming 250 ml/15 min of either a 6% (wt/vol) carbohydrate solution (C), a 6% carbohydrate + 4.2% MCT solution (C+M), or a sweet placebo (P). Time to complete the set amount of work was reduced in both C and C+M compared with P by 7 and 5%, respectively (C: 166 ± 7 min; C+M: 169 ± 7 min; P: 178 ± 11 min; P < 0.01). Plasma glucose concentration was maintained at or above resting values throughout both C and C+M trials but decreased (P < 0.05) below resting values in P at the completion of the TT. The estimated rate of carbohydrate oxidation was not different during the first 90 min of exercise but thereafter was reduced (P < 0.05) in P and was maintained in both C and C+M. These data demonstrate that carbohydrate ingestion during exercise improves 100-km TT performance compared with a sweet placebo, but the addition of MCT does not provide any further performance enhancement.

Original languageEnglish
Pages (from-to)113-119
Number of pages7
JournalJournal of Applied Physiology
Volume88
Issue number1
Publication statusPublished - 1 Jan 2000
Externally publishedYes

Keywords

  • Endurance exercise
  • Glucose

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