Anthony Joshua says secret to his success is punishing training schedule at Sheffield gym

The boxer, who successfully defended his IBF title and claimed the vacant WBA strap with a dramatic 11th round knockout of Wladimir Klitschko on Saturday, uses the city's English Institute of Sport as his training base.

And during a question and answer session at the centre he said the punishing training schedule led by GB Boxing coaches in the Steel City had driven him to success.

The 27-year-old told the audience that when he first came up north he had to complete the equivalent of a week's worth of training that he was doing at his previous gym in London into just a single day in Sheffield.

He added: "I started questioning if this was for me because I was not used to the level of hard work and being around elite athletes.

"But it taught me never to shy away from hard work and that hard work pays off and it gets you the result."

In a previous BBC documentary called Anthony Joshua: The Road to Klitschko, he said of the Sheffield base: "A lot of good fighters pass through Sheffield on the amateur system. It's a phenomenal place and I would not change it for the world."