Short-Term High-Intensity Interval Training on Body Composition and Blood Glucose in Overweight and Obese Young Women

This study was to determine the effects of five-week high-intensity interval training (HIIT) on cardiorespiratory fitness, body composition, blood glucose, and relevant systemic hormones when compared to moderate-intensity continuous training (MICT) in overweight and obese young women. Methods. Eighteen subjects completed 20 sessions of HIIT or MICT for five weeks. HIIT involved 60 x 8 s cycling at similar to 90% of peak oxygen consumption ((V) over dot(2peak)) interspersed with 12 s recovery, whereas MICT involved 40-minute continuous cycling at 65% of (V) over dot(2peak). (V) over dot(2peak), body composition, blood glucose, and fasting serumhormones, including leptin, growth hormone, testosterone, cortisol, and fibroblast growth factor 21, were measured before and after training. Results. Both exercise groups achieved significant improvements in (V) over dot(2peak) (+7.9% in HIIT versus +11.7% in MICT) and peak power output (+13.8% in HIIT versus +21.9% in MICT) despite no training effects on body composition or the relevant systemic hormones. Blood glucose tended to be decreased after the intervention (p = 0.062). The rating of perceived exertion in MICT was higher than that in HIIT (p = 0.042). Conclusion. Compared with MICT, short-term HIIT is more time-efficient and is perceived as being easier for improving cardiorespiratory fitness and fasting blood glucose for overweight and obese young women.