If You Think A 50 Mile Run Is Crazy...

Take a look at these other ultramarathons:

Badwater 135 - This is a 135 mile race in Death Valley - during the heat of the summer!
Western States 100 - A 100 mile race with over 38,000 feet of inclines and declines.
Massanutten Mountain 100 - This race is virtually run on rocks and boulders for most of the 100 miles!