The comparative effects of two different carbohydrate gels on post-exercise glucose and plasma free-fatty acids of long distance runners

Abstract

The purpose of this study was to determine the post-exercise glucose and free fatty acid (FFA) responses to two different carbohydrate gel (CHO gel) supplementations. Body composition and dietary intake of 8 long distance runners were assessed prior to a 90-min run at 70% VO2 max on a motorized treadmill. Blood samples were collected pre and post-exercise when they received 1 g.CHO.kg-1 orally, either as maltodextrin-glucose-fructose (MGF) or maltodextrin-glucose (MG) or placebo (P). In both MGF and MG trials, blood glucose levels increased similarly during the first 30 min of recovery in response to the post-exercise ingested CHO supplement. In the P trial, blood glucose levels remained unchanged during recovery. The area under the curve was higher after the consumption of MG than MGF during recovery. Plasma FFA levels decreased in both CHO supplement trials and remained suppressed during recovery when compared to the P trial (P<0.05). We conclude that supplement CHO gel MG trial induced different patterns of plasma glucose postprandial time 60 and 90 min after exercise. Plasma FFA levels showed similar responses after exercise, regardless of supplemental CHO (MG and MGF trials). Furthermore, the decrease on plasma glucose levels occurred earlier with MGF loading rather than MG alone.