Genetic Testing For Athletic Ability?

Looks like you can now test your kid(s) for a sports gene to determine if they would be better at speed & power sports, endurance sports, or some combination of the two. Apparently, this is determined by analyzing ACTN3 within the DNA makeup.

Seems to me like if you are raising a future Olympic athlete this might come in handy ... but in most cases I see it hindering the future of a child's athletic desires and abilities.

If a child is determined to be better at speed/power, should they never train for a marathion? Or will the mere fact of knowing the DNA makeup just simply take the idea of a marathon out of the life goals for that child? And is a boy's father going to force him into football because he is stronger in the speed/power arena? And what if that boy says he wants to be a cross-country runner instead? Is the answer "No, you are not genetically superior in that area?"

I am sure that Brooke is destined to be some sort of future Olympian, but I dont need a test to tell me that. As she grows up she will figure out what she is good at and where she is lacking and naturally gravitate to what she does best. Either way we will support her in whatever direction(s) she heads...and we dont need DNA testing to help us with that :)