Ultra runner is trying to break the fastest known time on the Appalachian Trail. He has to average approximately 50 miles per day for 2 months to do it. He's in Maine now on the ruggedest hence slowest parts of the trail. The record is held by a woman who did it hiking (rather than running) long days from 5 am to 10 pm. She chose hiking to save her joints. As the attached article says, if he breaks the record, it will be by a tiny margin, his original plan was to beat it by 4 days. It's a supported run meaning his cohorts do the cooking and tent work etc for him, he just eats, sleeps, and runs.
http://www.outsideonline.com/1997316/will-scott-jurek-break-appalachian-trail-record-maybe
http://www.outsideonline.com/1997316/will-scott-jurek-break-appalachian-trail-record-maybe