Fitness instructors do not belong to preaching teachers. Because fitness coach is a profession, it usually refers to a professional fitness coach or trainer, who is mainly responsible for teaching customers the correct posture, making personalized fitness plans, guiding exercise skills and providing suggestions on nutritious diet. Although fitness coaches also need to impart knowledge and skills to clients, their teaching scope is mainly about fitness, which is different from those teachers who teach education, science and technology, literature and other disciplines in schools, so fitness coaches are not didactic teachers.