Comparative effects of high-intensity interval training and moderate-intensity continuous training on soleus muscle fibronectin type III domain-containing protein 5, myonectin and glucose transporter type 4 gene expressions: a study on the diabetic rat model.

ABSTRACT

BACKGROUND: The increase in fibronectin type-III domain-containing protein 5 (FNDC5), myonectin, and glucose transporter 4 (GLUT4) leads to a decrease in diabetes; meanwhile, exercise training can affect these factors. The result regarding the comparison between the effect of high-intensity interval training (HIIT) and that of moderate-intensity continuous training (MICT) is confusing. Thus, the present study investigated the comparative effects of HIIT and MICT on soleus muscle FNDC5, myonectin, and GLUT4 gene expressions in the diabetic rat model. METHODS AND RESULTS: Seventy-two male Wistar rats (weight 200 g ± 20) were randomly and equally assigned to six groups control-healthy, MICT-healthy, HIIT-healthy, control-diabetes, MICT-diabetes, and HIIT-diabetes. At the first level, Streptozotocin (STZ) was utilized to induce diabetes in rats (at a dose of 55 mg/kg). After that, the training groups performed HIIT and MICT programs on the rodent treadmill for 6 weeks (five-session/week). Twenty-four hours after the last intervention, soleus muscle was removed, and sent to a research facility for future examinations. HIIT and MICT increased the muscle FNDC5, myonectin, and GLUT4 gene expression compared to the control group (P < 0.05). The type of training had no significant effect on the FNDC5 (P > 0.05), while the MICT program induced a greater increase in the myonec ztin and GLUT4 compared to the HIIT program (P < 0.05). Meanwhile, a positive relationship between all variables was observed. CONCLUSIONS: Exercise training has a beneficial effect on diabetes conditions via the effect of FNDC5, myonectin, and GLUT4. Due to the correlation between myonectin and GLUT4 shown in the present study, physical activity may alter myonectin through its effect on GLUT requiring further investigation by subsequent studies.