I wanna agree with Astid's husband. It depends on the sport. If it could be an income-earning thing, great. Yes, Olympic gold winners can get sponsors and make some money off those deals, but if you are at your peak (say in gymnastics) at 16, would that be enough to "make" you for the rest of your life?? (I don't know, so if anyone does, tell!)

Rugby is big here, so if my son is good in rugby (heaven forbid any of my children being gifted in a contact-sport ) sure I would get up at 4am to take him to training. Would I move to Jo'burg if one of the local clubs don't want to sign him??? or if that would give him a better change to play for South Africa?? That would be a family decision, because it would involve the WHOLE family moving and pitching in to help and supporting. I also believe that you have to spend just as much time on his emotional coaching as on his physical training. A child that has a great talent, needs to know how to handle the punches, the training, the critisism, the sceduals, the failures.
I also agree that a child with natural, God-given talent would thrive under decent coach, it has not to be the "best in the land" coach.

Also I would do it only if it's my CHILDS dream, not mine or his/her dad's. To push my daughter to be the swimmer I never got a chance to be, would be cruel and selfish. But if SHE wants it, who am I to stand in her way. But still, I would draw a line somewhere with swimming, because on it's own (over here) not much money in it.