Those are interesting articles but I also keep coming back to the benefit, as I always find myself doing. I don't have any doubt that training for and running a marathon is more beneficial to one's health than sitting on the couch and eating Cheetos all day long. However, why all or nothing? Why aren't we talking about two things: 1) more moderate levels of running for health benefits and 2) building up more gradually? I strongly suspect that more moderate levels of running would be better for one's health than training for and running a marathon and that taking more time to build up would reduce, though unfortunately not eliminate, the risk due to both better preparing the body for the rigors of the task and learning to know how one's body responds to stresses and when something is going wrong.