According to my understanding and observation, most people who go to fitness centers are people aged 20-50, and many of them have a certain economic foundation. Men mainly want to gain muscle, while some fat people want to lose weight and be healthier. Ladies mainly take part in some exercises, yoga, pilates, etc. to keep fit. You might say that you can exercise at home. There are fitness equipment in parks, communities and playgrounds. Now people's awareness of fitness is gradually enhanced. Most people who go to fitness voluntarily have a certain economic foundation. They pursue an atmosphere where they can get scientific and regular exercise. I believe that with the development of society and the improvement of people's living standards, more and more people will do this. In economically developed countries, such as the United States, many Americans are like this. Generally, large-scale fitness centers and international chain stores are relatively formal. Some fitness centers may have salesmen to trick customers, but after all, such customers will not last long, and they will never buy the second month after being cheated for one month, so basically those members are voluntary.