For relatively weak muscles, it is best to practice alone. If the body muscles are relatively balanced, it is best to practice with muscles of the same strength.

It is a classic practice to practice three chest heads and two back heads at the same time. First of all, it saves time and gives muscles a full rest. If you practice separately, each muscle can only be practiced once a week, and the amount can't meet the requirements. Moreover, after practicing back muscles, practicing two heads the next day will lead to lack of training or overtraining.

If which part of the muscle is weak, you can set aside a day to practice.

Conventional training methods are best carried out in such a group.