For many people, completing a marathon is the accomplishment of a lifetime. For others, racing 50 or even 100 miles is the ultimate challenge. Some people, however, seek out events that border on impossible. By combining extreme distances with rugged terrain, heat, cold, elevation, and route finding difficulties, these competitions-and those that complete them-compete for the title of toughest races in the world.
1. Marathon des Sables
Held in Morocco each year, the Marathon des Sables bills itself as the "toughest footrace on Earth." Participants cover 156 miles over the course of six days. During this time, they must traverse the Sahara desert crossing dunes, mountains, sand, and storms. Unlike other races on this list, the Marathon des Sables is a stage race meaning competitors stop each day and rest. The twist, however, is that they must also carry all of their own supplies-save a small ration of water given out each day-including food, clothing, a sleeping bag, and other items.
2. Badwater Ultramarathon