Scott Jurek has raced 135-miles across the scorched earth of Death Valley's Badwater Basin, and won. At Greece's Spartathlon, he retraced the 153-mile run of an Athenian messenger to the Battle of Marathon faster than anyone else — three times in a row. And at the Western States Endurance Run, he successfully conquered a 100-mile trail run — across the snow-capped peaks of the Sierra Nevada Mountains — seven times consecutively.

Now 41 and on the cusp of retirement, Jurek is currently running what he's referred to as his "masterpiece" — a 2,189-mile traverse of the Appalachian Trail from Georgia's Springer Mountain to Mount Katahdin in Maine.

Legendary ultra-runner David Horton is widely credited with establishing the first "fastest known time" (or FKT) for a supported thru-hike of the Appalachian Trail. For 52 straight days in the summer of 1991, Horton woke between 4 A.M. and 5 A.M. and ran up to 12 hours at a time. He claimed that after the first 1,000 miles, things got easier. In 2005 after two previously failed attempts, ultra-runner Andrew Thompson lowered the trial's FKT to 47 days, 13 hours, and 31 minutes. He lost 30 pounds over the course of his run across the Appalachians. And then in 2011, a slight and agile woman named Jennifer Pharr Davis broke Thompson's record by more than a day. Davis, who was supported by her husband, hiked the trail rather than running to lower the stress on her joints, and slept just six hours a night.

Though the community of AT-record attempters is a tight-knit one, Pharr Davis said she's made a decision not to follow Jurek's record attempt too closely. "It's easy to invest a lot of wasted emotional energy into other people's hikes," she said. (She also admitted — perhaps only half-joking — that "there's a sadistic joy in making someone suffer to break your record.")

Jurek's record attempt began in Georgia on May 27th (other record setters like Pharr Davis have set out from Mount Katahdin, to get the more difficult northern portion of the trail over with first) and he aims to arrive in Maine within 42 days. To do so, Jurek will need to average over 50 miles a day on the trail, and more brutally, gain and lose more than 12,000 feet in elevation per day. Jurek's wife, Jenny, is his primary support, meeting him at road crossings in their outfitted Sprinter van, in which they also sleep. But Jurek and Jenny aren't in this alone, hundreds of people have met Jurek along the trail to offer encouragement and momentarily run beside him, including the Appalachian Trail record pioneer David Horton. (In fact, Jurek has gained such a following, his wife asked fans to remember her husband is pursuing a record and cannot stop for photo-ops with everyone.)

Pharr Davis says failed AT-record attempts typically hinge on three excuses: "You got hurt, you got sick, and then a storm came." So far, Jurek's overcome two of the three typical record-ending obstacles. Just four days into his AT-record attempt, Jurek suffered severe knee pain, and a subsequent quad strain, forcing him to take a day off from running. He's since made up for the lost mileage and regained his goal pace. But on Sunday, as he approached the Vermont border, he was forced to run through a storm with winds and rain so severe it blew down trees.

Jurek's still on the AT, and is on pace to arrive at Maine's Mount Katahdin on July 6.

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