Related books and contents, such as sports anatomy, sports nutrition, sports physiology, sports biomechanics, health and fitness, personal trainer's basic exercises, are all areas that every fitness instructor must master. In addition, related books, such as functional training courses, joint function rehabilitation courses, free joint rehabilitation, cardiopulmonary resuscitation, basic psychology, fitness and bodybuilding, training principles and training plan formulation, sales courses, etc. You also need the involvement of a fitness instructor, not to mention mastery, at least you can know a lot of knowledge and use it flexibly in your work.