Muscles have memory function, and once they are professionally trained, they will never forget this state. In order to adapt to this change, muscles have to be rearranged and grown. Therefore, after proper exercise, muscles or muscle groups will experience moderate fatigue, and their shape and function will decline to some extent. Through proper rest, muscle strength, shape and function can be restored to the level before exercise, and can continue to rise and exceed the original level in a certain period of time. With the extension of rest time, it gradually falls back to its original functional level. If you do the next exercise at the stage of excessive recovery (muscle function rises and exceeds the original level for a period of time), you can keep the excessive recovery from fading and gradually accumulate the exercise effect. In this way, through repeated muscle strength exercises, muscle volume can be increased and muscle strength can be enhanced.