%0 Journal Article
%T Gender impacts the post-exercise substrate and endocrine response in trained runners
%A Lisa M Vislocky
%A P Courtney Gaine
%A Matthew A Pikosky
%A William F Martin
%A Nancy R Rodriguez
%J Journal of the International Society of Sports Nutrition
%D 2008
%I BioMed Central
%R 10.1186/1550-2783-5-7
%X After consuming a euenergetic diet (1.8 g，kg-1，d-1 protein, 26% fat, 58% carbohydrates, 42.8 ＼ 1.2 kcal/kg body weight) for 8 days, blood was collected from trained male (n = 6, 21 yrs, 70 kg, 180 cm, 9% body fat, VO2peak 78.0 ＼ 3.4 mL，kg FFM-1，min-1) and female (n = 6, 23 y, 66 kg, 170 cm, 29% body fat, VO2peak 71.6 ＼ 4.5 mL，kg FFM-1，min-1) endurance runners at rest and during recovery from a 75 min run at 70% VO2peak. Circulating levels of glucose, lactate, free fatty acids (FFAs), insulin, cortisol, growth hormone (GH), and free insulin-like growth factor I (IGF-I) were measured.During the recovery period, females experienced increases in glucose, lactate and insulin while no changes were noted in men (P < 0.05). Males experienced increases in GH and decreases in IGF-I levels respectively (P < 0.05) while no changes were observed in females. FFA levels increased during recovery from endurance exercise, but changes were not different between genders.These data further document gender differences in substrate and endocrine changes during a prolonged recovery period following endurance exercise. Future studies are needed to evaluate the effect of differing diets and nutritional supplements on these gender-specific post-exercise substrate and endocrine differences.Fat and carbohydrates are the primary fuel sources used by muscle during aerobic exercise [1]. Intramyocellular triglycerides (IMTGs) and plasma free fatty acids (FFAs) are the primary sources of fat while muscle glycogen and blood glucose are the major sources of carbohydrates provided to working muscle. Endogenous protein is not a major fuel source during exercise [2]. While protein oxidation will increase as exercise intensity increases [3] and/or individuals become glycogen depleted [4], its contribution to total energy production remains minimal. In general, the relative contribution of each substrate to energy production is complicated by many factors such as exercise intensity, duration, subject trai
%U http://www.jissn.com/content/5/1/7