The Effect of Two Types of High Intensity Interval Training (HIIT) on Oxidation of Fat and Carbohydrate in Young Overweight Men

The aim of this study was to investigate the effects of two weeks of high-intensity interval training (HIIT) on fat and carbohydrate oxidation in overweight young men. 16 young sedentary overweight men participated voluntarily in this study and were randomly assigned to two experimental groups: HIIT-1 (BMI=26.54±2.6) and HIIT-2 (BMI=26.32±2.29). HIIT-1 included 3 sessions a week with four 1-min. intervals, and 4 min. of rest and HIIT-2 included four 30-sec. intervals with 2 min. of rest. Respiratory gasses were collected one day before and after the training in a fasting state for laboratory analysis. Independent t test was used to analyze intergroup changes while dependent t test was applied for intra-group analysis. The results showed that HIIT decreased 9% of carbohydrate consumption and increased 43% of fat consumption, when Bruce test was conducted in HIIT-1. These changes were significant compared with HIIT-2. The changes of weight and body fat percentage were significant only in the HIIT-1. According to these results, 6 sessions of HIIT relatively improved fat oxidation and glycogen storage.