Abstract: Objective: To determine the effectiveness of high-intensity interval training (HIIT) on body mass and body fat percentage in overweight and obese adults, in comparison with moderate-intensity continuous training (MICT). Methods: Four electronic databases (PubMed, Embase, Web of Science, and the China National Knowledge Infrastructure) were searched for randomized controlled trial (RCT) or clinical controlled trial (CCT) comparing the effect of HIIT and MICT on body mass and fat percentage in overweight and obese adults. The risk of bias assessment was performed for each of the included studies. The meta-analysis was performed by using STATA 13.1. Results: Ten studies, including 119 participants in HIIT and 114 participants in MICT, met the eligibility criteria and were included in the meta-analysis. No statistically significant difference between HIIT and MICT was observed for body mass (WMD=-0.18,95% CI:-1.03～0.66,P=0.67) and fat percentage (WMD=-0.38, 95% CI: -1.02～0.27, P=0.25). However, a significant reduction in body mass following HIIT compared with MICT was observed in subgroups "48 times" (WMD=-1.51,95% CI:-2.73～-0.29,P=0.016), while marginally significant reduction in fat% following HIIT compared with MICT was observed in subgroups "12 weeks" (WMD =-0.73, 95% CI: -1.49～0.03, P=0.061) and "48 times" (WMD=-1.14,95% CI:-2.43～0.15,P=0.084). Conclusion: The effects of HIIT and MICT

Key words: High-intensity Interval Training, Moderate-intensity Continuous Training, Overweight, Obesity, Body Fat Percentage, meta-analysis