Dean Karnazes didn’t go for his first serious run until the night of his thirtieth birthday. What he found was that he could just keep running without getting tired.

Since that night Dean had gone on to run some pretty incredible running feats. He has run 50 marathons in 50 days, 350 miles in 80 hours and 44 minutes, without sleep not to mention completing a 135-mile ultra-marathon in Death Valley, California in temperatures of 120F (49C).

So what makes Dean so special? Turns out his body is a little different to yours and mine. Find out all about it on Futureproof this Saturday from 10am.

Here’s Dean on Conan O’Brien just after he had completed the 50 marathons :