Muscle glycogen supercompensation: absence of a gender-related difference

Recently it has been reported that women do not have the capacity to accumulate supranormal levels of muscle glycogen when subjected to a carbohydrate (CHO) loading regimen [Tarnopolsky et al. (1995) J Appl Physiol 78:1360-1368]. Since, in this study, CHO intake relative to body mass in the female subjects was much lower than that in males, our primary aim was to reexamine this issue using subjects fed comparable amounts of CHO. Endurance-trained female and male subjects ingested 12 g CHO.kg(-1) lean body mass.day(-1) in conjunction with the cessation of their daily physical training. A 3-day exposure to this diet resulted in a marked rise in muscle glycogen levels from [mean (SD)] 108 (15) mmol.kg(-1) wet weight to 193 (14) mmol.kg(-1) wet weight and 111 (16) mmol.kg(-1) wet weight to 202 (20) mmol-kg l wet weight in the female participants during the post-menstrual and pre-menstrual phases of their menstrual cycle, respectively, and from 109 (27) mmol.kg(-1) wet weight to 183 (25) mmol.kg(-1) wet weight in males. We conclude that (1) female athletes have the capacity to accumulate supranormal levels of muscle glycogen, and (2) when exercise-trained males and females are fed comparable amounts of CHO relative to lean body mass, there is no gender-related difference in their ability to accumulate supranormal levels of muscle glycogen.