Abstract: Objective: To systematically evaluate the effects of high-intensity interval training on patients with non-alcoholic fatty liver disease. Methods: A systematic and comprehensive literature search was conducted for randomized controlled trials examining the effects of high-intensity interval training in patients with non-alcoholic fatty liver disease in PubMed, Cochrane Library, Embase, Web of Science, CINAHL, CNKI, WanFang Data, VIP, and SinoMed. The search timeframe was from the establishment of the databases to November 1, 2023. Meta-analysis was performed using RevMan 5.4 software after 2 researchers independently screened the literature, extracted relevant information and quality assessment. Results: Fourteen papers with a total of 598 patients with non-alcoholic fatty liver disease were finally included. Meta-analysis results showed that high-intensity interval training was effective in reducing visceral fat [MD=-7.84, 95% CI (-13.19, -2.50), P=0.004] and improving liver function (ALT) [MD=-4.99, 95% CI (-6.31, -3.67), P<0.001], (AST) [MD=-2.63, 95% CI (-3.79, -1.47), P<0.001], and improving quality of life [MD=0.98, 95% CI (0.78, 1.18), P<0.001] and peak oxygen uptake [SMD=1.51, 95% CI (0.77, 2.24), P<0.001]. The effects of high-intensity interval training on LDL cholesterol, total cholesterol, and triglycerides were statistically significant, while the effect on HDL cholesterol was not significant [MD=-2.71, 95% CI (-0.22, 5.65), P=0.070]. Conclusion: High-intensity interval training can reduce visceral fat, increase peak oxygen uptake, improve cardiopulmonary function, and enhance the quality of life of patients with nonalcoholic fatty liver. However, further research is needed to improve patients' high-density lipoprotein cholesterol.

Key words: high-intensity interval training; non-alcoholic fatty liver disease; Meta-analysis