Effects of HIIT and Sprint Interval Training on Adiposity in Overweight Adults: A Meta-analysis.

A meta-analysis was conducted to compare the effects of high-intensity interval training and sprint interval training on body fat reduction in adults with overweight or obesity. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, eight databases were searched, yielding 10 relevant studies involving 343 participants. Both high-intensity interval training and sprint interval training significantly reduced body fat% (standardized mean difference=- 0.56, 95% confidence interval=(- 0.89,-0.24), and p=0.001 and standardized mean difference=- 0.57, 95% confidence interval=(- 0.85,-0.29), and p=0.000, respectively), fat mass (standardized mean difference=- 0.62, 95% confidence interval=(- 1.01,-0.23), and p=0.002 and standardized mean difference=- 0.51, 95% confidence interval=(- 0.81,-0.21), and p=0.001, respectively), and body mass (standardized mean difference=- 0.43, 95% confidence interval=(- 0.75,-0.11), and p=0.009 and standardized mean difference=- 0.34, 95% confidence interval=(- 0.58,-0.10), and p=0.006, respectively). No significant differences were found between high-intensity interval training and sprint interval training in terms of body composition changes. However, the time spent on sprint interval training was approximately 50% less than that of high-intensity interval training. Subgroup analysis suggested that sprint interval training with shorter work durations (less than 10 s) was more effective in obesity control. In conclusion, both high-intensity interval training and sprint interval training demonstrated similar effectiveness in improving body adiposity. Given its time efficiency and straightforward intensity monitoring, sprint interval training may serve as a viable alternative exercise program for promoting fat reduction in adults with overweight or obesity, provided that it is appropriately designed.