The Effect of an Eight-Week Low-Volume High-Intensity Interval Training Compared to Moderate-Intensity Continuous Training on Liver Enzymes and Anthropometric Indices: A Comparison of Obese and Lean Men with Non-Alcoholic Fatty Liver Disease

Introduction: Nonalcoholic fatty liver disease (NAFLD) is a prevalent metabolic liver disorder associated with insulin resistance, excess adiposity, and increased cardiovascular risk. Although obesity is a major risk factor, many individuals with NAFLD are lean, and their responses to exercise remain unclear. This study compared the effects of eight weeks of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on liver enzymes and anthropometric indices in obese and lean men with NAFLD. Methods: In this quasi-experimental study, ۵۶ men with ultrasound confirmed NAFLD (grade ≥ ۲) were randomly allocated to four groups: obese + HIIT, obese + MICT, lean + HIIT, and lean + MICT. Participants completed supervised exercise sessions three times per week for eight weeks. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), body mass index (BMI), and waist to hip ratio (WHR) were measured before and after the intervention. Between group differences were analyzed using analysis of covariance (ANCOVA), with baseline values as covariates. Effect sizes were reported using partial eta squared (η²). Results: After adjustment for baseline values, no significant between-group differences were observed for ALT or AST, although both enzymes showed numerical reductions in all groups. Significant between-group differences were found for anthropometric outcomes. HIIT produced greater reductions in BMI (p < ۰.۰۰۱, partial η² = ۰.۳۸) and WHR (p < ۰.۰۰۱, partial η² = ۰.۲۹) than MICT, with the greatest improvements observed in obese participants. Conclusion: An eight-week HIIT program was more effective than MICT in improving body composition, particularly overall and central adiposity, in men with NAFLD. Although exercise was associated with favorable trends in liver enzyme levels, these changes did not reach statistical significance between groups. These findings support HIIT as a time efficient strategy for improving anthropometric outcomes in men with NAFLD.

کلیدواژه ها:

Non-Alcoholic Fatty Liver Disease ، Body Mass Index ، Waist Hip Ratio ، Alanine Transaminase ، Aspartate Aminotransferases