Is it good for your body to run a marathon?

I do sprint triathlons and modest foot races (up to about 5 miles or 8 kilometers) for general fitness and personal reward, but I've never done a marathon or even a half marathon. Nor do I expect ever to attempt one, since the regimen to prepare for one is grueling even under the best of circumstances. So I'm a participant in distance and endurance sports (even in middle age), but my events are modest in comparison to the marathon.

My appreciation is that the human body is pretty well adapted to the sustained effort of a marathon. If you have never heard of it, do a web search for "persistence hunting" to find out how and why humans are able to outrun big game. However, that example is for people well conditioned to spend essentially all day running. For most of us, we definitely have a limit to how much time and energy we can stress the body before it begins to consume itself and break down. That can take the form of "hitting the wall" or it can be total and complete systemic collapse. In the first case, recovery is relatively fast and there are few if any lasting deleterious effects. In the second case, such as with heat stroke, it can be fatal. The more common example of bad results obtained from running the marathon is using up the knees over time, which is often a combination of poor technique, questionable use of running shoes, and carrying too much body weight.

This answer was edited by Brvtvs 154 days ago.

Reason: typo