Knee pain after a few days of exercise may be caused by soft tissue injury, osteoarthritis, calcium deficiency, etc., which can be relieved by rest, physical therapy, and taking anti-inflammatory and pain relieving medications such as ibuprofen. 1. Soft tissue injury: If the patient’s exercise is too large, it may cause soft tissue injuries such as meniscus and ligament around the knee, which should stop the exercise immediately and take bed rest to relieve the pain and reduce the weight-bearing activities of the knee. Can take ibuprofen and other drugs to relieve treatment. 2. Osteoarthritis: is caused by degenerative osteophytes in the knee joint, the pain is aggravated after exercise, the patient can take a hot compress to promote blood circulation, accelerate metabolism and promote recovery. You can also massage to relieve the pain. 3. Calcium deficiency: children and adolescents have prominent symptoms of calcium deficiency, which can lead to knee pain after exercise, and can be treated by taking calcium supplements. If the pain does not improve after the above treatment, the patient should go to the hospital for treatment. The above medications should be taken under the guidance of a physician.