marathon runners

As I have written in my recent posts entitled "Marathon Lessons from a Novice," I am running my first marathon in less than one month. (1) With the event quickly approaching, I have been wondering a lot about marathons in general.
Given the popularity of marathons and participation in the United States exceeding half a million annually, a Yale-led team of researchers sought to explore the relationship between strenuous exercise and kidney function. (1)