The appearance of gym is based on people's demand for physical exercise, and it is also a concrete manifestation of social and economic development to a certain level. As for which groups will go to the gym, they must be fitness enthusiasts, but whether they are absolutely rich or not is not necessarily true, but at least they have enough food and clothing! Of course, many people can't go to the gym because of working hours. Different occupations, even if you have money, you don't have time to go to the gym.