Nutrition and Exercise Determinants of Postexercise Glycogen Synthesis

Abstract

During the initial hours of recovery from prolonged exhaustive lower body exercise, muscle glycogen synthesis occurs at rates approximating 1-2 mmol·kg−1wet wt·if no carbohydrate is consumed. When carbohydrate is consumed during the recovery, the maximal rate of glycogen synthesis approximates 7-10 mmol·kg−1wet wt·. The rate of postexercise glycogen synthesis is lower if the magnitude of glycogen degradation is small, if less than 0.7 gm glucose·kg−1body wt·is ingested, when the recovery is active, and when the carbohydrate feeding is delayed. The rate of postexercise glycogen synthesis is not reduced during the initial hours (< 4) after eccentric exercise. For studies evaluating muscle glycogen synthesis in excess of 12 hours of recovery, average rates of glycogen synthesis are balow 4 mmo1·kg−1wet wt·. Glycogen synthesis is known to be impaired for time periods in excess of 24 hours following exercise causing eccentric muscle damage. Following intense exercise resulting in high concentrations of muscle lactate, muscle glycogen synthesis occurs at between 15-25 mmol·kg−1wet wt·. These synthesis rates occur without ingested carbohydrate during the recovery period and are maintained when a low intensity active recovery is performed.