It is not appropriate to ice the knee after exercise. Ice can be taken when there is redness, swelling, heat, pain, and a local inflammatory reaction. Inflammatory reaction is a stress reaction of the body in the late stage of surgery and can be taken by ice. The knee is one of the large weight-bearing joints of the body, and excessive cold stimulation can lead to secondary damage to the muscles and joints after exercise. After the cold enters the knee joint, the knee joint will become painful when the weather changes, so icing after exercise is not recommended, which is not conducive to the recovery of human bones.