In the present study the effects of hyperglycemia (i.e.,12 mmolll) throughout prolonged intense exercise on carbohydrate metabolism were examined. Eight male subjects undertook two trials during which they exercised on a cycle ergometer at an intensity of -70% Vozmax for 120 min. In the first trial (trial A), subjects had their blood glucose concentration clamped at 12 mmolll, 30 min before exercise and throughout exercise, The same rate and volume of infusion of 0.9% saline as had occurred for trial A
were used in a placebo trial (trial B).
Calculted of the rates of total carbohydrate oxidation showed that trial A
resulted in significantly higher values when compared with trial B (P
The results of this study confirm that maintained hyperglycemia promotes carbohydrate oxidation and glucose uptake, and it does not effect sparing
muscle glycogne. However hyperglycemia may spare other carbohydrate sources, especially hepatic reservoirs.
)