Oddly enough, swimming gives you hella grip strength. I had no idea, until I realized I could 'play' a coworker's hand-exercise gadgets like castanets. Up to now, I've just thought it was useful for when people handed me bottles to open.

OTOH, decades of breathing air from just above a chlorinated (or brominated) pool surface can't have been good for me - but I live in a place where the outdoor water surface gets stiff part of the year...