People reflexively downvote DeVany's observations to their own peril.<p>While some of that list is anecdotal, most is based on relevant studies, and on DeVany's long interest and observation of patterns of health (as an athlete and economist). His perspective is a necessary antidote to the popular conception that ever-longer distance-running delivers a monotonically-increasing level of healthiness.<p>DeVany suggests -- with evidence -- that instead, the optimal activity involves bursty, varied, intense exertion more than marathon-like exertion. The stresses and rhythmic pace of marathoning damage some systems more than they help.