Although a good coach may not practice well, he must have won some games, but he must not practice badly. For example, someone teaches you to lift weights, weigh 90kg, and do extreme squats of 120kg. Do you dare to let him teach you? Teach you the fitness system. I 185, weighing 70kg. Although I have six packs of abdominal muscles, do you dare to let him teach me? Teach you physical fitness … I really don't know how to define physical fitness … forget it, stop it! Many people say that we should pay attention to face value, forget it, please! Although a good coach is not necessarily an expert in sports physiology and sports nutrition, such as telling the composition of muscles in one breath, what to consume first and then what to consume to the limit weight, a bunch of seven or eight technical terms make you dizzy. But at least you should be able to see at a glance what's wrong with your posture, what you can practice, what you need to pause, and correct your posture before you start. I will also distinguish between what I can solve and what you have to go to the hospital to solve. (Most people have various postures and physical problems, which some fitness instructors can't solve at all) This is very important!