Exhaustion refers to practicing in a set of training until you can't do it anymore, that is, going all out for the last time. And outside the gym, no one's activities will reach exhaustion. A man who digs for a living will never dig until he can't carry a shovel, and a porter will never move until he can't carry it any more. However, these people who are good at rough work all have extraordinary muscles. What promotes muscle growth is the increase of training intensity. If the intensity has been increased but not used up, it doesn't matter whether you do it for the last time. It doesn't matter how many times. Fatigue is irrelevant. The only factor that works is the improvement of strength.