The world’s longest footrace is, of course, not the marathon. A measly 26.2 miles (42.2 km), the furthest distance in mainstream athletics is only a stepping stone for many to the “ultramarathon” race distances: 50 km, 50 miles (80 km), 100 km, 100 miles (160 km) and beyond. The most legendary of these ultramarathons include the 89 km Comrades marathon in South Africa, the 217 km scorching Badwater race through California’s Death Valley, and the six-day, 251 km Marathon des sables in the Sahara.