I have no problem believing that marathons may be harmful to the human body. The reason I run marathons isn't primarily for the races themselves but rather for the motivation the races provide to get in shape. You can't easily wing it or cram for a marathon (Lord knows I've tried), so the races' looming deadlines provide an escalating urgency to one's workouts. The resulting workouts are fairly short (amateurs rarely run full marathons in training, and only hit high distances near the end), intense, and irregular (ie, increasing over time with rest days interspersed as opposed to the same routine every day) -- qualities which match DeVany's own recommendations for how to exercise as related in the TimesOnline article. For a guy who preaches that one should consider the whole of complex systems, his dismissal of marathons considers only the tip of the iceberg. I believe that the health benefits associated with my training will more than make up for whatever health risks I may face on race day.