It would be an understatement to say that my friend Stephanie likes to run. It would be overstating the case to claim that she lives to run. The truth would be somewhere in between, as it is for a lot of runners. It isn't so much that running becomes a part of life, but more that it becomes something of an organizing principle of life. As it is for casual runners, so it is even more for ultra-runners, the small minority who will rip off a 10K for fun before spending six days running around an indoor track in Alaska. Those were the people who took part in Six Days in the Dome, an event to which Stephanie alerted me and which I knew instantly I needed to cover. The result was this piece for ESPN , which is accompanied by a terrific photo gallery by Jeffrey Genova.