Pain when bending the knee after exercise can be relieved by hot compresses and slow walking if the pain is physiological. If it is caused by knee injury, it can be treated by rest, medication or even surgery. If the intensity of the exercise is too high, the knee structure will be pulled to cause a transient physiological pain, which can be gradually recovered through rest, massage and slow walking. If the knee continues to ache when bending after exercise, it may be due to strains on the joint capsule, ligaments, etc. and meniscus injuries caused during exercise. To pay attention to adequate rest, it is best to be able to do bed rest, the pain is obvious can be oral anti-inflammatory analgesic drugs to relieve pain, such as nimesulide, diclofenac sodium and so on. If the medial collateral ligament is ruptured, it can also be treated by surgical repair. If there is pain when bending the knee after exercise, it is recommended that the patient go to the hospital for a complete examination and receive regular treatment. The above drugs should be used under the guidance of a doctor, avoid self-medication.