Objective: Physical exercise is a well-established therapeutic method in type 2 diabetes treatment. The purpose of this study was to investigate the effects of eight weeks combined and High Intensity Interval Training on serum apelin levels and pancreatic β-cell function in overweight women with type 2 diabetes mellitus. Materials and Methods: Fifty-two overweight female patients with type 2 diabetes (aged 45-60 years old, BMI> 30) with HbA1c>6. 5% participated in the study voluntarily. The participants were assigned to High Intensity Interval Training (HIIT) group (n= 17), combined training group (n= 17), and control group (n= 18) according to their HbA1c levels. The exercises included 12 weeks of combined training and HIIT. Levels of HbA1c and fasting glucose and insulin were measured. Results: There was a significant decrease in the fasting blood glucose in the HIIT groups (P-value: 0. 001). Serum insulin levels showed significant increases in the HIIT (P-value: 0. 001) and combined training groups (P-value: 0. 001). Changes in apelin level were not significantly different within HIIT and combined training groups (P-value: 0. 13 and 0. 09, respectively). The data showed significant differences in pancreatic β-cells function in HIIT (P < 0. 001) and combined training groups (P= 0. 003). Furthermore, the ANCOVA test showed that there were no significant differences in fasting blood glucose concentrations (F= 1. 853, P-value: 0. 171), apelin (F= 0. 511, P-value: 0. 12). However, significant differences were observed between groups in insulin (F= 3. 622, P-value: 0. 036), and β-cell function (F= 4. 243, P-value: 0. 003). Conclusion: Physical exercise is an effective training method to improve glycemic control in woman with type 2 diabetes.