Objective: In diabetes the production of free radicals and inflammatory agents in the heart tissue is increased and the expression of genes associated with the induction of apoptosis is altered. Considering the importance of common cardiovascular disorders in diabetes, this study investigated the effect of eight weeks of aerobic exercise and kerosene use alone, as well as tissue damage and oxidative stress caused by diabetes in the heart of adult rats. Materials and Methods: To induce diabetes, streptozotocin 50 mg/kg was injected as a single dose intraperitoneally. After 72 hours, blood glucose levels were monitored by a glucometer, and blood glucose above 250 mg/dl was considered diabetes. Continuous treadmill exercise was performed for eight weeks by placing the animal on the treadmill. Next, the animals were anesthetized, and samples were taken from the hearts and frozen in liquid nitrogen. Then, superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) were measured in the cardiac tissue. Finally, the hearts of half of the animals were immediately immersed in formalin solution for histological changes. Results: According to our findings, diabetes increased lipid peroxidation, which was characterized by increased MDA levels in the control diabetes group and decreased SOD and GPx levels (P <0.05). It also changes the balance of expression of genes associated with apoptosis control, increased Bcl-2-associated X (Bax) expression, and decreased Bcl-2 expression (P <0.05). Also, we observed the induction of apoptosis in cardiac tissue. Using eight weeks of continuous exercise and administration of crocin significantly reduced blood sugar levels and lipid peroxidation and increased the activity of antioxidant enzymes and Bcl-2 gene expression compared to the diabetes control group. In addition, continuous exercise and kerosene improved the oxidative stress parameters in the control group. Conclusions: The results of this study showed that diabetes could cause oxidative stress and heart dysfunction. Moreover, simultaneously and separately, aerobic exercise with treadmill and crocin administration can reduce these disorders and prevent apoptosis in the heart tissue.