Objective Diverse management for diabetes have been developed, however, the pathogenic treatments are still limited in the diabetic peripheral neuropathy(DPN) except strict glucose control and a few agents including alpha lipoic acid. And exact effectiveness of supportive care such as exercise are not clear in the DPN. We investigated the effect of regular exercise on the peripheral nerve in the STZ induced diabetic rats. Methods The animals were divided into six groups according to the exercise and glucose control:Normal group, Normal with exercise (EXE), diabetic group(DM), DM + EXE, DM + glucose control with insulin (INS), and DM + INS + EXE. Animals of exercise were walked on treadmill machine everyday for 30 minutes at the 8m/min without inclination. After 16 weeks, biochemical, sensory parameters, and quantification of peripheral nerves were compared. Results Fasting blood glucose and HbA1c levels were not influenced by exercise in normal and DM groups. However, current perception threshold (CPT) and von frey stimulation test showed higher threshold in the DM + INS + EXE than DM + INS group (P < 0.05) although significant differences were not observed in the other groups according to the exercise and significant lower thresholds were observed in untreated DM groups (DM or DM + EXE) compared with normal and insulin treated DM groups. Intraepidemal nerve fiber density (IENFD) was less reduced in the DM+INS+EXE group than DM + INS group (9.8 ± 0.4 vs 9.1 ± 0.5, P < 0.05), however, exercise did not give a significant benefit in IENFD in other groups. Sole exercise couldn`t show protective effect on the peripheral nerve significantly in normal and DM group, however, beneficial effect was observed when hyperglycemia was controlled with insulin in DM group. Conclusion These findings suggest that exercise has a protective potential against DPN based on the fundamental effort for glucose control.