How’s this for one of the craziest physical challenges I’ve seen: The Everest Marathon.

Starting at Everest Basecamp (17,149 ft), the race is run 26.2 miles to Namche Bazaar (11,300 ft). Now, from someone who’s been there, this is not just a straight downhill run - you’re constantly gaining and losing altitude and having to deal with acclimatizing. It took us several days to hike it - I can’t even imagine running it.

For those who are interested, an entry form is here.