Badwater 135

The Badwater Ultramarathon claims to be the world's toughest footrace, and it has a fair case for it. The race begins in Death Valley, California's Badwater Basin. There are 282 feet below sea level there. The race travels 217 kilometers (135 miles) to Mount Whitney, which rises to 8,360 feet above sea level. All of this, plus mid-July Death Valley temperatures that have reached 57 degrees Celsius at times. With a record high temperature at the starting line in 2018, 30 racers dropped out.

Runners must learn how to deal with the extreme conditions. Dehydration can be fatal, and even means of staying cool might be hazardous. All runners must travel with a crew, and water must be provided at all times. Ice water melts quickly, and many runners carry ice on their bodies, which can be dangerous as it melts and causes chafing. The road gets so hot that even shoes have melted. Runners can finish the race in 20 to 40 hours and consume 65 liters of water or more during that time. Along the way, runners may suffer from heat exhaustion and other severe side effects. Hallucinations are not uncommon. One runner who finished the race in 2019 reported falling asleep a few times while running.

Founder: Chris Kostman

Established: 2016

Location: Badwater Basin, in California's Death Valley