It sounds to me like there are more factors involved than just the CAH. Neither of my CAH kids show any propensity for being athletic, nor any propensity for not being athletic. It would seem that some kids naturally take to physicla things, while others don't.

Teddy Roosevelt was considered a weakly child, he later became known as a great outdoorsman, because he hated the idea of being weak and asthmatic. He fought it and over came it. I would say pretty much any child could do the same thing if they were motivated.