Thigh soreness on the second day of running is usually caused by lactic acid buildup, and you can still go on running. If you have sore thighs on the second day of running, you can still run, but you need to do a good job of warming up before running, such as leg stretching, lunge leg press, knee and ankle exercises, jumping in place, etc., so that the whole body’s muscles and joints can enter the exercise state as soon as possible, so as to avoid injuries in the process of running. At the same time, it is also necessary to appropriately reduce the time and distance of running, and then gradually increase the intensity of running afterwards. If the symptom of thigh pain on the second day of running is more serious, it may be the thigh muscle ligament strained, which is not relieved after resting, it is recommended to go to the orthopedic department of regular hospitals as soon as possible to cooperate with the doctor to conduct the relevant examination and treatment under the guidance of the doctor. Running exercise, pay attention to scientific exercise, prevent sports injury.