This seems more intuitive. Better athletes being quick on their feet figuratively as well as literally. This (and confidence) may be a reason that athletes make good salespeople. And it could explain why so many are traders.

I've seen much less as research professors or computer programmers. This could also be because the time commitments required in school for these topics is inconsistent with what's required to do sports competitively.

I'm not saying that exercise is bad. I'm positive that it's good. It's just my perception that those who exercise more in their youth tended not to be the best students.