Show: Tough Mudders
Watch It Here

Tough Mudders is a day-long competition held in the US in which men and women try to complete a muddy obstacle course. All of the challenges are pretty gruesome (anyone up for the Ball Shrinker?), but Fire Walker takes the cake.

Contestants must walk through a field of burning straw, with flames rising to four feet. The site warns that if contestants can't hold their breath, they will inhale carcinogens. Remember, people volunteer for this,