Have you heard of the Tough Mudder? It is a series of obstacle course competitions and it is known as “the toughest one day event on the planet." The photos below were taken in Scotland during a Tough Mudder.
My brothers and cousins did this race last year in New Jersey. I went to go watch them and it was quite the experience! Some of the race looks like a blast (jumping and crawling in the mud), but some of it is insanely tough. The race is usually about 10 miles on top of completing the obstacles throughout the race. They have to run through electrical wires, jump in freeing cold water, and run through fire!
Source posted by Julia