Comparison of the effects of high‑intensity interval training and moderate‑intensity continuous training on indices of liver and muscle tissue in high‑fat diet‑induced male rats with non‑alcoholic fatty liver disease

چکیده مقاله

Background: Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases. It is shown that moderate to high physical activities can play a crucial role in improving this disease. Aim: The purpose of this study was to explore the effects of high-intensity interval training (HIIT) and moderateintensity continuous training (MICT) on the levels of the myonectin in serum and tissue levels and fatty acid transport protein 4 (FATP4) in male rats with NAFLD. Materials and methods: Thirty-three male rats were randomly divided into five groups: high-fat diet to confirm NAFLD induction (n = 5), normal diet sedentary (n = 7), high-fat diet sedentary (n = 7), high-fat diet with HIIT (n = 7), and high-fat diet with MCIT (n = 7). Induction of NAFLD was performed by feeding rats for 12 weeks with a high-fat diet containing 60% fat. The training protocols were performed in five sessions per week for 8 weeks. The HIIT group has performed 4 × 4 min interval running on a treadmill up to 80–95% maximal oxygen uptake (VO2max) and then recovered at 50–60% VO2max. The MICT protocol has performed up to 50–60% VO2max for 50 min. myonectin and FATP4 were also measured by the animal Elisa kit (Zellbio, Germany) with a sensitivity of 0.02 ng/L. Insulin resistance was evaluated by the insulin resistance homeostasis assessment index using the following formula (HOMA-IR): “fasting glucose (mg/dl) × fasting in insulin (mg/L) ÷ 405”. One-way ANOVA analysis of variance was utilized for statistical analyses and Tukey’s post hoc test at a significant level of p < 0.05. Results: The 8-week intervention showed that both HIIT and MICT positively influenced the serum myonectin and FATP4 levels (p < 0.05). Moreover, there was a significant difference between the trained groups in tissue levels of the myonectin and serum levels of FATP4 (p < 0.05). Conclusions: Altogether, both HIIT and MICT can lead to valuable adaptations and recovery of NAFLD in male rats.