Plasma glucose kinetics during prolonged exercise in trained humans when fed carbohydrate
Data(s) |
01/09/2002
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Resumo |
Nine endurance-trained men exercised on a cycle ergometer at ~68% peak O<sub>2</sub> uptake to the point of volitional fatigue [232 ± 14 (SE) min] while ingesting an 8% carbohydrate solution to determine how high glucose disposal could increase under physiological conditions. Plasma glucose kinetics were measured using a primed, continuous infusion of [6,6-<sup>2</sup>H]glucose and the appearance of ingested glucose, assessed from [3-<sup>3</sup>H]glucose that had been added to the carbohydrate drink. Plasma glucose was increased (<i>P < </i>0.05) after 30 min of exercise but thereafter remained at the preexercise level. Glucose appearance rate (R<i>a</i>) increased throughout exercise, reaching its peak value of 118 ± 7 µmol · kg<sup>-1</sup> · min<sup>-1</sup> at fatigue, whereas gut R<sub>a</sub> increased continuously during exercise, peaking at 105 ± 10 µmol · kg<sup>-1</sup> · min<sup>-1</sup> at the point of fatigue. In contrast, liver glucose output never rose above resting levels at any time during exercise. Glucose disposal (R<sub>d</sub>) increased throughout exercise, reaching a peak value of 118 ± 7 µmol · kg<sup>-1</sup> · min<sup>-1</sup> at fatigue. If we assume 95% oxidation of glucose R<sub>d</sub>, estimated exogenous glucose oxidation at fatigue was 1.36 ± 0.08 g/min. The results of this study demonstrate that glucose uptake increases continuously during prolonged, strenuous exercise when carbohydrate is ingested and does not appear to limit exercise performance. <br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
American Physiological Society |
Relação |
http://dro.deakin.edu.au/eserv/DU:30008524/hargreaves-plasmaglucosekinetics-2002.pdf http://dx.doi.org/10.1152/ajpendo.00443.2001 |
Direitos |
2002, The American Physiology Society |
Palavras-Chave | #Glucose uptake #Glucose production #Glycogenolysis |
Tipo |
Journal Article |