Changes in Mitochondrial Dynamic Factors (mfn۲ and drp۱) Following High Intensity Interval Training and Moderate Intensity Continuous Training in Obese Male Rats

Objective: Mitochondrial content and function are important determinants of oxidative capacity and metabolic efficiency of skeletal muscle tissue. The aim of this study was to investigate the changes in mitochondrial dynamic factors (mfn۲ and drp۱) following high intensity interval training (HIIT) and moderate intensity continuous training (MICT) in obese male rats. Materials and Methods: In this experimental study, ۴۰ male wistar rats after inducing obesity with high fat diet (for ۱۰ weeks), eight rats from the high-fat diet group (O) and eight rats of the standard dietary group (C) were sacrificed and other obese rats were randomly divided into three groups: obesity control (OC), MICT and HIIT groups. The HIIT protocol includes ۱۰ bouts of ۴-minute activity with intensity of ۸۵-۹۰% vo۲max and ۲-minute active rest periods and MICT protocol with intensity of ۶۵-۷۰% VO۲max with covered distance was matched to that of HIT protocol for ۱۲ weeks and ۵ sessions per week. Protein levels of mfn۲ and drp۱ soleus muscle were measured by Western blot. For analyzing the data, One-way ANOVA and Tukey post hoc with SPSS–۲۳ and the significance level was P-value≤ ۰.۰۵. Results: Induction of obesity was associated with a significant decrease in soleus muscle mfn۲ and drp۱ (P-value= ۰.۰۰۱). The intervention of HIIT and MICT significantly increased of mfn۲ and drp۱ compared to control group (P-value= ۰.۰۰۱). Also, mfn۲ and drp۱ were significantly higher in HIIT compared to MICT group (P-value= ۰.۰۰۱). Conclusion: It seems that HIIT and MICT increase the mitochondrial dynamic factors in skeletal muscle, and the effects of HIIT are significantly higher