The pair are set to meet in what is being billed as the biggest fight in British boxing history at Wembley Stadium a week on Saturday (April 29).
Around 90,000 spectators will cram into London’s biggest sporting arena to roar on Joshua in his sternest test to date.
And the former Olympic gold medallist looks in tip-top shape with the fight creeping closer by the day.
In a clip uploaded by iFL TV, AJ continues his strength and conditioning work with a series of incredibly painful looking neck stretches made famous by Mike Tyson.
The former heavyweight champion utilised a similar stretching routine to build his ferocious physique that saw him finish with a career record of 50-6-2.
Thousands have seen the video since it was posted on YouTube earlier today.
“I tried doing this on my bed and now I’m in hospital,” joked one viewer.
Another said: “AJ’s physique is ridiculous. Which heavyweight boxer was as big, thick and ripped as AJ?
“At 6ft 6ins, I don’t think anyone comes close.
“I sometimes wonder if he is the Usain Bolt of boxing, the guy who breaks the rules and all dimensions of what the perfect boxer should be. Only time and performances will tell.”