PURPOSE: This study examined the effects of mildintensity exercise (MIE) and high-intensity interval exercise (HIIE) on the recovery of the motor function over time in sciatic nerve crush injury rats. METHODS: The MIE group ran on a treadmill at a speed of 8.3 m/min to perform low-intensity training with maximum oxygen uptakes ranging from 40 to 50%. The HIIE group ran on the treadmill at a speed of 25 m/min to perform high-intensity training with a maximum oxygen uptake of 80%. The interval training was performed based on a 1:1 work-to-rest ratio. The effects of each form of exercise on the rats' walking abilities following their recovery from the peripheral nerve injuries were evaluated based on the results of behavior tests performed at one and 14 days. RESULTS: According to the test results, the MIE group