The time to prepare for the activity can be determined according to the specific situation of the practice content, which is generally 10? 30 minutes is good. The intensity and amount of exercise are not large, and the amount of exercise should be controlled at 100? 120 times/minute. The interval between formal exercise (main part) and formal exercise is generally not more than 15 minutes, and formal exercise can be carried out immediately after completing the warm-up activities.