Can male-only institutions still survive in today's world?

I’d like to open a gym for men only. Gyms for women are all over the place, as well as other female-only institutions. This is perfectly fine. But the classic old men’s clubs seem to be dying out or being forced to accept female membership. There aren’t really any male-only spaces in the modern world. I’m not sure if the same would apply to gyms. So would a gym that does not accept female membership, for the explicit reason that they are female, be able to function without being dragged before every tribunal in the state?