Big Dog’s Backyard Ultra is the toughest, weirdest race you’ve never heard of, says BBC Sport’s Justin Goulding. Endurance runners from around the world converge on a sprawling Tennessee farm to run laps of a scruffy 4.16666 mile track through the woods. How many laps? Nobody knows. You just keep running one lap an hour until there’s only one person left.
“It’s like being punched in the face,” says race organiser Gary Cantrell, “again and again and again.” The record, held by a Belgian dentist, is 75 hours, or 312 miles. The race is intentionally demeaning: “jeerleaders” line the track to heckle runners and the inflatable banner at the finish line reads “There Is No Finish”. Along with the usual blisters and twisted ankles, runners regularly hallucinate. “It’s all in your head,” says Cantrell, who launched the event a decade ago to test which runners were the toughest mentally, rather than the fastest or fittest. “It’s a war between your mind and your body.”