99% of the world's fitness crowd and athletes' anaerobic exercise/muscle-building methods are carried out through group exercise. Generally speaking, there are 4 groups for each movement, with 8~ 12 for each group. According to the training intensity and the training effect to be achieved in the plan, the interval rest time is between 30 seconds and 30 minutes. Moreover, athletes and ordinary bodybuilders now adopt the method of group exercise because a large number of scientific experiments and examples show that muscles can be stimulated more and grow faster through group exercise, and when the number of groups is 4 and the number of times is 12, the muscle stimulation reaches the maximum and the growth is the best. Because heavy weight can completely destroy muscle fibers, and 12 repetitive actions can use relatively more muscle fibers, such repetitive actions and groups are most conducive to muscle growth.