Fury is jealous of my body, says Joshua
Joshua, 26, faces American IBF champion Charles Martin in London on Saturday in a bid to win the belt that Fury was stripped of in December for refusing to fulfil a mandatory fight.
Fury last week branded Joshua “useless” and predicted that he will lose to Martin because “this game is not all about body-building”.
Joshua fired back: “They’re hating on my beach body. They’re just hating, that’s what it is. If they want, I’ll give them some sessions. They can come train with me if they want.
“I asked them to spar, they don’t want to spar. They don’t want to work, so they can stay there, but this is just how I am. I ain’t got no comments on his physique. This is just how I am.
“There’s a lot of jealousy, a lot of negativity, so that’s why I shut it down and just focus on myself.”
Joshua, the 2012 Olympic gold medallist, has won all 15 of his professional fights to date by knockout.
The burly Fury, 27, has a less impressive physique than Joshua, but produced a cultured performance to out-point long-term heavyweight champion Wladimir Klitschko in November.
Fury and Klitschko are expected to fight in a rematch later this year.