High intensity interval training is superior to moderate intensity continuous training improves insulin resistance probably via increasing circulating spexin

Objectives: Obesity by decreasing adipokines involve in insulin resistance such as spexin is associated with insulin resistance. The aim of this study was to evaluate and compare the effects of high intensity interval training (HIIT) and aerobic training on serum levels of spexin and insulin resistance in overweight women.
Methods & Materials: Thirty overweight women (BMI> 25 kg/m2) voluntarily participated in this study. Subject were divided into three groups; HIIT, aerobic training and control groups. HIIT training was included 4 ×4-min at 85-95% maximal heart rate interspersed with 3-min active recovery periods. Aerobic training was included 37 minutes of moderate intensity. Both protocols were matched for calorie expenditure. Body weight and blood samples were measured before and 48 hours after last training session. Insulin, glucose, insulin resistance index (HOMA-IR) and spexin were evaluated. Data were analyzed by ANCOVA and paired t test.
Results: The results showed that HIIT was associated with higher serum spexin levels compared to the control group (P=0.001). Furthermore, both training protocols decreased insulin, glucose and HOMA-IR in comparison with the control group (P=0.0001). However, there were no significant differences between two exercise training groups in insulin, glucose, insulin resistance and spexin (P> 0.05).
Conclusion: The findings suggest that HIIT by increasing serum spexin partly improves insulin resistance in overweight women.