Purpose: Exercise has been shown to be a simple and economical therapeutic modality that may be considered as an effective aid for diabetic mellitus. For example, exercise training increases insulin sensitivity in type 2 diabetes. But we found no reported of how exercise affect type 1 diabetes. This study investigated the impact of aerobic and graduated treadmill exercise regimens on body weight, glucose and insulin concentrations, lipid profiles, and oxidative stress indicators in rats with streptozotocin (STZ) induced diabetes. Glycosylated hemoglobin ($HbA_{1c}$) was determined as an indicator of glucose control during exercise. Methods: In our study, a total of 40 rats were used. Three groups of 10 rats each were given STZ to induce diabetes. The remaining 10 rats became the normal group. After 28 days we determined biochemical parameters such as glucose, glycosylated hemoglobin ($HbA_{1c}$), insulin concentration, serum total cholesterol (TC), triglycerides (TG), and high-density lipoprotein (HDL). Superoxide dismutase (SOD) and catalase activities were also measured. Results: Concentrations of blood glucose and $HbA_{1c}$ in the moderated exercise groups were significantly decreased after 28 days compared with the control group (p<0.05). There was a significant reduction in serum TC and TG in the experimental groups. The activity of SOD increased significantly by 17.70% and 48.25% respectively. Conclusion: These results indicate that physical training and exercise training affects body weight, fasting blood glucose, $HbA_{1c}$, insulin, lipid profiles, and antioxidant status in rats with streptozotocin-induced diabetes. We suggest that graduated treadmill exercise may have therapeutic, preventative, and protective effects against diabetes mellitusby improving glycemic control, oxidant defenses, and lipid metabolism.