Anthony Joshua is my sparring partner and I am an unbeaten heavyweight. His punches feel like being struck with a sledge hammer

ANTHONY JOSHUA’S punches are like being hit with a SLEDGE HAMMER – his sparring partner brutally revealed.

The two-time heavyweight champion is one of the hardest hitters in the division, with 22 knockouts in his 25 wins.

And heavyweight contender Frazer Clarke – managed by AJ – opened up on what it is like to take a whack from the superstar fighter.

Clarke told The Independent: “There’s a comparison of hitting something with a sledgehammer, or hitting something with a normal hammer a lot of times – you know, like when you hit a nail.

“[The latter] is what it is with Joshua, then he’ll finish you off with a sledgehammer on the last shot. Boom.”

Clarke, 31, spent several years on the Team GB squad with Joshua, 33, sharing hundreds of sparring rounds.

And after bronze at the Tokyo Olympics, he turned professional and is now 7-0 with five KOs.

Joshua meanwhile, is in talks to return in the summer having beaten Jermaine Franklin, 29, in April.

Dillian Whyte, 35, has been sent an offer to rematch AJ but a clause in the contract held the bout up.

Joshua is also negotiating a Saudi Arabia super-fight against Deontay Wilder, 37, for December.

And Clarke sent out a fierce warning to AJ’s heavyweight rivals having been on the end of his famed power.

He said: “It’s not nice. It’s not nice being hit by any heavyweight.

“You only have to look at Anthony Joshua, the man is made of muscle – he has muscles coming out of places where muscles shouldn’t be – but when people think about Joshua punching, what they don’t realise is… it’s not the one punch. He’s actually a really good combination puncher, and a fast puncher.”

“When he gets the opportunity, he punches hard and often, and that’s almost worse than one single shot.

“You can prepare for a single shot – you can sort of brace on impact – but what you can’t prepare for is two, three, four shots from different angles.”