Effects of high and low glycemic isoenergetic breakfast on glucose homeostasis and substrate oxidation during high intensity intermittent exercise

Abstract

Summary Objective The purpose of the present study was to investigate the effect of high glycemic (HGI) and low glycemic (LGI) isoenergetic breakfast on glucose homeostasis and substrate oxidation during high intensity intermittent exercise (HIIE). Methods On two occasions, 7 days apart, eight healthy and practiced men with age (23.4 ± 0.9 years) maximal oxygen uptake (53.7 ± 1.0 mL/kg/min) participated in this trial. At each stage, 60 minutes after consumption isoenergetic breakfast, completed HIIE. Blood samples collected in 6 stages for measuring plasma glucose, insulin and glucagon. Results The results showed that in the postprandial period, plasma glucose and insulin concentrations in HGI were higher than LGI (P Conclusion HGI causes hyperglycemia and hyperinsulinemia in the postprandial period, and higher levels of insulin before exercise can lead to a sudden drop in blood glucose over the course of the exercise, but LGI, due to lower insulinemia, helps to maintain better blood glucose and Glucose homeostasis during HIIE. LGI also increases fat oxidation, which can save carbohydrates.