Low-Frequency High-Intensity Interval Training (HIIT) Improves Cardiorespiratory Fitness and Body Composition in Overweight Adults

888 Board #149 May 30 3

30 PM - 5

00 PM

PURPOSE: This study examined the effects of 8 weeks of low-frequency high-intensity interval training (HIIT) on cardiorespiratory fitness and body composition.

METHODS: Twenty-three overweight/obese young men (mean age 22.7 ± 2.8 years, BMI 25.5 ± 1.8, percent body fat 22.3 ± 2.2%) were randomly assigned to HIIT and no- intervention control (CON) groups. Participants assigned to HIIT group performed 12 bouts of 1-min 30-meter shuttle runs at 90% of heart rate reserve (HRR), interspersed by 1-min of active recovery at 70% of HRR once weekly. Participants in control group were instructed to maintain their daily lifestyle habit for 8 weeks. VO_2max was measured by beep test and body composition was assessed by bio-impedance segmental body composition analyzer before and after the study period.

RESULTS: VO_2max was significantly increased after 8 weeks of HIIT intervention (HIIT +17.5% vs. CON -0.3%). Total body fat mass, percent body fat and waist circumference were significantly reduced after 8 weeks of HIIT intervention (fat mass: HIIT -7.9% vs. CON +4.7%, percent body fat: HIIT -7.6% vs. CON +2.9%, waist circumference: HIIT -4.5% vs. CON +0.8%).

CONCLUSION: Our results demonstrate that low-frequency HIIT (i.e., performed once weekly) improves cardiorespiratory fitness and body composition in overweight/obese men.

Supported by HKU Seed Fund for Basic Research