Requirements for becoming a fitness instructor: you need to master professional fitness theory knowledge and skills. Theories to be mastered: sports biomechanics, human anatomy, physiology, psychology, nutrition, etc. Skills to master: resistance training, aerobic exercise and equipment use, stretching exercise, physical training. The national fitness instructor certificate is a certificate recognized by the state. The training time for people with basic knowledge is relatively short, which takes about several weeks. If it is a zero-based exam, the fitness instructor should start learning basic fitness skills and professional fitness skills.