You'd be forgiven for thinking that Tim Fitzhigham is a bit on the bonkers side. He's rowed the English Channel in a bath tub, paddled the Thames in a paper boat, run 40 miles in 40 degree heat wearing a suit of armour, and it seems that most of his more maniacal stories stem from finding ideas to pop into his yearly Fringe shows (which shows an admirable dedication to the cause).

This year, the aptly-titled Challenger focuses on not just one madcap scheme, but a literal series of them for a TV show Superhuman Challenge. Fitzhigham swoops from story to outlandish story with a wild-eyed, sweaty manner that is instantly arresting. Meeting a number of world record holders and attempting to better their unique skills leads him to try arrow catching and double decker bus pulling; his storytelling ebbs and flows, handily illustrated by video clips and pictures for proof.

Although Fitzhigham steers clear of mawkish sentimentalism, the ultimate discovery of his own most unlikely superpower is a fitting finale to his journey, both witty and, in an odd way, inspiring.

Pleasance Courtyard, 556 6550, until 26 Aug, 7.30pm, £9.50–£12.50 (£8.50–£11).