Marathon de Sables
Distance: 154 miles
This is one of the biggies. It’s been running since 1986 and since it’s inaugural year with 23 competitors has blossomed into one of the most high profile of the big challenge races. Some stretches of the sand as so fine that the run actually becomes a trek. Avoiding mid-summer temperatures by running the race in April helps a bit but temperatures regularly get up to very high 30s.