The first is, of course, the rapid development of first-tier cities with large development space.

Although the development space of second-tier cities is large, the consumption power of first-tier cities is also very high in other cities.

Third, if you want to be a fitness instructor, you might as well choose a second-tier city, so that you can have a salary comparable to that of a first-tier city and a good spending power of a second-tier city.