I believe it was the New England Journal of Medicine that some time ago had an article about bicycling, and that it seemed to slow down the aging process. Would think that any regular exercise would do that, but cycling was specifically discussed. Might be something to it--I've had more than one person ask how old I was, after I'd been trail riding and taken my helmet off while getting a drink and cooling down. Most express surprise that a "senior" is riding the trails they may have just finished riding. BTW--nothing too extreme-at least these days--but not so tame either.