Distance: "Eight country miles"

Location: South Staffordshire, England

Mode of Transportation: Run, crawl, swim, etc.

Sure, a lot of the races and challenges on this list are extreme, grueling and exhausting – but how many make the competitors sign a death waiver before competition? Perhaps just one: Toughguy. What is Toughguy? That’s a good question.

The actual event varies slightly from year-to-year (save for the cross-country run to begin), but simply put, it’s the obstacle course from Hell. Past hazards have included The Fiery Holes (series of muddy, water-filled ditches, coupled with burning bales of hay), The Viet Cong Tunnels (cement pipes underground), The Tiger (a climb up and down two 30-foot nets, with electrified cables in between) and the Stalag Escape (a crawl through the mud and underneath barbed wire; "One year, [they] shot live ammo over the heads of people crawling under the barbed wire”).

Perhaps this sums it up best: “We have searched the world amongst military and security forces to find any unit with a more demanding ONE DAY survival training ordeal. The US Navy S.E.A.L.S. 'Grinder' Assault Course is our nearest rival.”