Elite athletes aren't just fitter than the rest of us -- certain parts of their brains are likely bigger than ours, too. As Wired reports, "[j]ust like the muscles of the body, [athletes'] brains operate as finely tuned machines: Increasing evidence supports the idea that there are measurable differences in the size not only of their biceps but certain areas of their brains."
[I]n one of the brain areas studied, the researchers found that the number of years each athlete competed as a diver nearly predicted how thick the subject’s brain would be. If the results of this small study hold, there may be some biological truth to the adage, “practice makes perfect.” It’s as if each year of sports experience becomes neatly folded as a new layer of neurons atop previously mastered skills, physical knowledge, and competition know-how that have already been crammed into the brain.[Source]