TTuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: he effects of low and high glycemic index foods on exercise performance and beta-endorphin responses | Jamurtas et al. Journal of the International Society of Sports Nutrition 2011 8 15 http content 8 1 15 jissn journal of the international lociety of rporti nutrition RESEARCH ARTICLE Open Access The effects of low and high glycemic index foods on exercise performance and beta-endorphin responses Athanasios Z Jamurtas Trifon Tofas loannis Fatouros Michalis G Nikolaidis Vassilis Paschalis Christina Yfanti1 2 Stefanos Raptis4 and Yiannis Koutedakis1 2 5 Abstract The aim of this study was to examine the effects of the consumption of foods of various glycemic index values on performance b-endorphin levels and substrate fat and carbohydrate utilization during prolonged exercise. Eight untrained healthy males underwent in a randomized counterbalanced design three experimental conditions under which they received carbohydrates gr. kg-1 of body weight of low glycemic index LGI high glycemic index HGI or placebo. Food was administered 30 min prior to exercise. Subjects cycled for 60 min at an intensity corresponding to 65 of VO2max which was increased to 90 of VO2max then they cycled until exhaustion and the time to exhaustion was recorded. Blood was collected prior to food consumption 15 min prior to exercise 0 20 40 and 60 min into exercise as well as at exhaustion. Blood was analyzed for b-endorphin glucose insulin and lactate. The mean time to exhaustion did not differ between the three conditions LGI min HGI min placebo min . There was a significant interaction in glucose and insulin response P with HGI exhibiting higher values before exercise. b-endorphin increased significantly P at the end of exercise without however a significant interaction between the three conditions. Rate of perceived exertion heart rate ventilation lactate respiratory quotient and substrate oxidation rate did not differ between the three conditions. The present study indicates that ingestion of foods of different glycemic .
