Challenge? H

E’S the heavyweight champion of the world, after defeating the six-foot-six Ukrainian man mountain Wladimir Klitschko.

But, while Anthony Joshua might be King of the Ring, he’s about to be taken massively outside his comfort zone, where he is completely clueless and – frankly – terrified.

The lad from Watford admits he knows nothing about the great outdoors, hates heights and bugs, and is more used to sitting in his lounge playing computer games.

So survival expert Bear wastes no time in chucking AJ in at the deep end or, more precisely, dangling him from a helicopter.

They’re being flown to the notorious Commando Ridge in Cornwall, a daunting and challenging climbing face where the Royal Marines have trained since the Second World War.

First he’ll have to drag that 17 stone of pure muscle up the exposed granite cliffs, tackling sharp pinnacles, squeezing himself through tiny spaces, having to make a tricky descent when they’re faced with a ‘death drop’ on all sides.

And the culinary reward for all this effort? Some maggots and a rotten sheep leg. Haute cuisine, this is not. Then the next day it’s the biggest challenge – AJ has to abseil 200 feet down the sheer cliff by himself.

He might be standing at the top giving his famous beaming smile, but as he prepares to lean back and jump off he also admits it’s the “scariest thing he’s ever done.”

If you’re thinking this all sounds a bit macho – rock climbing and male bonding, boxing training and chats about fatherhood – you’d be right.

These are big manly men doing big manly men things. But there’s also a bit right by the end when handsome AJ takes his top off to rappel down some rocks and then dives into the sea. Just saying.