Effects of High-Intensity Interval Training on Fat Loss and Metabolic Markers in Middle-Aged Men

Abstract

The purpose of this study was to investigate the effect of uphill high-intensity interval training (6%, uHIIT) and moderate-intensity continuous training (MCT) on body composition, metabolic syndrome markers and endurance parameters in overweight middle-aged men. Following 12 weeks training the pre and post assessments on body composition, metabolic markers and endurance performance were conducted on 25 overweight middle-aged men (BMI ＞ 24). After pre-test, participants were randomly assigned into uHIIT, MCT and control groups. Participants in uHIIT group (heart rate control at 90% HRmax) performed 2-min interval running training and 1-min rest between intervals for 7 bouts in 20 minutes MCT group participants (heart rate control at 65% to 70% HRmax) performed continuous running for 40 minutes, whereas control group participants were trained 3 times a week for 12 weeks. The results indicated that uHIIT and MCT significantly improved the VO_2max, anaerobic threshold and time to fatigue, while decreased the fat percent of buttocks compared to control. Moreover, the increased amount of VO_2max in uHIIT group was pronounced than MCT group. The resting blood pressure, percent of whole body fat and leg fat were significantly improved only in uHIIT group. We conclude that both uHIIT and MCT improved endurance capacity, but only uHIIT decreased the body fat and blood pressure in overweight middle aged men. Other metabolic syndrome markers may not be affected by the exercise training in this study. The uHIIT was superior training method than the MCT in fat loss. The exercise intensity should be valued while doing exercise.