Marathon through the Jungle

Some are calling it a death march, but these few people are either all in it for the sport or for just pure craziness. These "super-humans" raced across 149 miles of the Amazon Rain Forest in just one weeks time. During their journey they encountered all dangers of the jungle, battling through swamps, bugs, animals, sickness, and fatigue. Most of the competitors made it strongly up to the third day, but the stress finally got the better of them as they had to throw in the towel. There were checkpoints at the ends of each days for the remaining contestants as they were given the chance to rest for the night. The real challenge then came, as part of the fifth day was all throughout the night as they made their way through the dangers of the dark. At the end of the 149 mile journey; only 13 of the 55 competitors remained, as the rest had given into the treacherous depths of the Jungle.  

Link to the video-
http://abcnews.go.com/Nightline/video/extreme-marathon-amazon-jungle-15805620