PURPOSE: The aim of this study was to compare the effects of different loading swimming exercises on muscle recovery after sciatic nerve crush injury in rats. METHODS: For this study, thirty-one Sprague-Dawley male rats were randomly divided into five groups. There were the negative control group (NCG, n=5), the positive control group (PCG, n=7), the low intensity swimming exercise group (LISEG, n=7), the moderate intensity swimming exercise group (MISEG, n=7) and the high intensity swimming exercise group (HISEG, n=5). Each rat was weighed to determine the lead weight to be attached to the base of its tail. Subsequently, the PCG, the LISEG, the MISEG and the HISEG were underwent standard unilateral sciatic nerve crush. The LISEG (no load), the MISEG (lead weight equivalent to 2% average body mass) and the HISEG (lead weight equivalent to 4% average body mass) were received the 10 minute swimming exercise in a day for 10 days. The NCG and PCG were not received with any therapeutic intervention. The diameter of the calf muscle and the level of serum lactate dehydrogenase (LDH) were measured to detect the effects of the swimming exercise. RESULT: The maximum diameter of the calf muscles was significantly increased after seventh swimming exercise in the LISEG, the MISEG and the HISEG compared with the PCG (p<0.05). However, there was no statistically significant difference between the LISEG, the MISEG and the HISEG. Also, the level of the serum LDH was significantly decreased in the LISEG, the MISEG and the HISEG compared with the PCG (p<0.05). CONCLUSION: Taken together, these results suggest that swimming exercise could accelerate muscle recovery processes after crush injury, but the different intensity of the swimming exercise does not affect healing processes.