It is suggested that 17-35-year-old friends who want to be fitness instructors should not deteriorate with age. Personal development in the fitness industry is very flexible and there are many business opportunities. The benefits of long-term fitness far outweigh the costs. Personal fitness trainer is a professional and skilled job. The more experienced you are, the more popular you are. With more experience, the old coach can naturally understand the physical condition and needs of many people, give accurate fitness guidance and make fitness plans. If you especially love the fitness industry, you can relax your age appropriately if your physical conditions permit.