Acute effect of low and moderate glycemic index drinks on plasma glucose level in professional football players during prolonged intermittent exercise

Abstract

Carbohydrate is the main fuel for muscles during exercise and depletion of glycogen stores has been associated with the onset of fatigue. However, scientific evidence of the importance of carbohydrate in energy supply in athletes is still conflicting. The aim of the study was to evaluate changes of the plasma glucose in professional athletes-football players-during prolonged exercise after intake of drinks with different glycemic index (GI). In total, 24 athletes participated in the study. During two 90-min exercise sessions of football training games, the plasma glucose level was measured every 15 min. In the first session changes of plasma glucose level were measured after consumption of a low GI drink, and in the second session after consumption of a moderate GI drink. The results of the study indicated that plasma glucose level did not differ significantly over a 90 min intermittent exercise after ingestion of moderate and low GI drinks.