Sore legs the next day after some sudden heavy exercise is due to the anaerobic metabolism of the muscles during strenuous exercise producing a large amount of lactic acid, which accumulates in the muscles and causes muscle soreness. Usually no special treatment is needed, it will gradually be metabolized by the body’s kidneys and the soreness will improve. If you want to improve this symptom quickly, you can drink more water, urinate more, and do not continue with heavy sports activities. If you have kidney function abnormal patients, not suitable for this large amount of exercise activities, because too much lactic acid will increase the burden of kidney metabolism, and even cause some kidney function abnormalities. The next day after squatting, the thigh pain, to drink more water, more urination, you can use local hot compresses to help the absorption of lactic acid, metabolism; if the pain is obvious, you can take some ibuprofen and other pain medication.