Boxing: Anthony Joshua shows off his title defence preparations

British boxing champion Anthony Joshua. Photo / Getty Images

Anthony Joshua is stepping up his preparation for this month's title defence, and showed off his impressive physique to his Instagram followers.

Joshua - who beat American Charles Martin to win the heavyweight title in April - faces Dominic Breazeale at The O2 on June 25 in his first defence.

And the 26-year-old posted a picture of himself in training on Friday as he gears up for the London bout.

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'Welcome to the KO show June 25th,' wrote the former Olympic champion alongside a picture of himself snarling at the camera as he worked out.

Earlier this week Joshua had paid tribute to the late Muhammad Ali, as well as admitting his fear of suffering long-term brain damage in the ring.

'Two things,' he said when asked about his fears. 'Losing all I have worked so hard for and being unable to provide for my son's future. And secondly, the effect boxing is having on my brain.

'I know if I don't look after myself I will be talking to you in a couple of years' time mumbling my words, and slurring. It won't be because I am drunk it will be the fighting, taking blow after blow to the brain.

'That scares me. I don't worry about being killed in the ring, it's losing my mind that I fear.'

Joshua also donned a t-shirt with Ali's name on the front and '1971 World heavyweight championship' - the year of the fight of the century when he lost to Joe Frazier in New York.