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Exogenous carbohydrate oxidation from drinks ingested during prolonged exercise in a cold environment in humans.

Authors :
Galloway SD
Wootton SA
Murphy JL
Maughan RJ
Source :
Journal of applied physiology (Bethesda, Md. : 1985) [J Appl Physiol (1985)] 2001 Aug; Vol. 91 (2), pp. 654-60.
Publication Year :
2001

Abstract

Six healthy male volunteers performed four rides to exhaustion on a cycle ergometer at approximately 80% of maximal oxygen consumption. Subjects ingested a bolus volume of fluid (7.14 ml/kg) immediately before exercise and additional fluid volumes (1.43 ml/kg) every 10 min during exercise. The fluids ingested were either a flavored water control or glucose-electrolyte beverages with glucose concentrations of 2, 6, or 12%. The beverages were labeled with [U-(13)C]glucose (99.2%: 0.05 g/l). Exercise capacity was not different (P = 0.13) between trials; median (range) exercise time was 83.52 (79.85--89.68), 103.19 (78.82--108.22), 100.37 (80.60--124.07), and 94.76 (76.78--114.25) min in the 0, 2, 6, and 12% trials, respectively. The oxidation of exogenous glucose in each 15-min period was significantly lower in the 2% trial (P = 0.02) than in the 6 and 12% trials where oxidation rates were between 0.5 and 0.7 g/min. No difference in endogenous glucose oxidation was observed between trials (P = 0.71). These findings indicate that the oxidation of exogenous glucose during exercise of this intensity and duration in a cold environment is similar to that observed in warmer conditions. Thus a low oxidation of exogenous substrate is unlikely to be a factor limiting the effectiveness of carbohydrate-electrolyte drink ingestion on exercise capacity in a cold environment.

Details

Language :
English
ISSN :
8750-7587
Volume :
91
Issue :
2
Database :
MEDLINE
Journal :
Journal of applied physiology (Bethesda, Md. : 1985)
Publication Type :
Academic Journal
Accession number :
11457777
Full Text :
https://doi.org/10.1152/jappl.2001.91.2.654