SYSTEMIC EFFECTS OF INGESTING VARYING AMOUNTS OF A COMMERCIAL CARBOHYDRATE BEVERAGE POSTEXERCISE

Objective: Although the role of postexercise carbohydrate intake in th e replenishment of muscle glycogen is well established, large amounts of carbohydrate may affect other systems which are recovering from exe rcise as well. Methods: We varied the timing and amount of a commercia l glucose polymer/fructose (CHO) beverage ingested postexercise in 2 g roups of 8 normotensive men following 1 hour of cycling exercise. In S tudy A the subjects ingested 1 L of a 200 g CHO solution or I L of wat er (W) immediately postexercise. The participants in Study B consumed 1 L of a 1.5 g/kg CHO solution, or W, immediately and 2 hours postexer cise. Results: Recovery systolic blood pressure was elevated after 200 g CHO as compared to water, but not after 1.5 g/kg CHO. Diastolic blo od pressure was decreased, while heart rate, insulin and glucose incre ased following both doses of CHO. Despite the potassium (K) content of the beverages, serum It decreased in Study A and B, while a trend was noted following CHO for decreased urinary K excretion at 2 hours and for increased sodium excretion at 4 hours in Study B. Post CHO aldoste rone declined more rapidly than after W, and urine volumes were decrea sed compared to W in both studies 2 hours after CHO. Conclusions: We s peculate that hyperinsulinemia contributed to the rapid decline in K a nd aldosterone by creating a flux of K to the intracellular space. It appears that CHO ingestion postexercise results in systemic effects th at are related to the amount and timing of CHO consumed.