Lactic acid accumulation is caused by lactic acid in glycolysis metabolism in strength training; The destruction of muscle microstructure will heal in the recovery period after training, and the healed muscle will become thicker than the original muscle fiber. This is called the principle of excessive recovery, which is the driving force of muscle growth. Train the target muscle with an ice pack immediately after heavy exercise training, usually for 10 to 15 minutes. The ice pack is separated from the skin with clothes or towels to prevent frostbite. Or take a cold bath The national weightlifting team has a special ice and snow room in the heavy sports hall of the General Administration of Sport. In order to speed up the recovery after heavy training, the national team members wear underwear and enter the ice and snow room with the temperature set at 0 degrees.