@Psy **
it has to do with visa and work permit. You can't freelance as a sports trainer. If you have enough money you might be able to start a gym, but you would need to employ minimum 4 thai national before you could even be considered for a work permit etc. It's not easy like "hey, let's move to another country and work as a freelance trainer". Ask yourself - could a thai person come to your country, get the visa to stay long term and get a work permit for a "random" freelance job, that many of your countries citizen can do as well? Most likely not... it would not be easy.