(Photo: PA)It's the toughest race on Earth. Oh, it's shorter than a marathon....  ...e on Earth. Oh, it's shorter than a marathon. The Tough Mudder is only 5 miles long. But along that race, contes...  ...m of Breadstone, Gloucester, UK, wanted to do the Tough Mudder . But 2 yea...

[YouTube Cli...  ...things. Participants on a 10-to-12 mile Tough Mudder course wade through waist-deep mud, c...  .... The events and their aura of all-out toughness hold special appeal to people in comp...