Ben Affleck found it "challenging" training for his role as Batman.

Ben Affleck

Ben Affleck

The 43-year-old actor - who has taken on the titular role in the hotly-anticipated movie 'Batman v Superman: Dawn of Justice' - admits he struggled with the tough regime to become a "real superhero".

Speaking from the red carpet at the 'Batman v Superman: Dawn of Justice' European premiere tonight (22.03.16), he said: "I'd already seen Henry [Cavill] topless in 'Man of Steel' so I knew what I had to live up to so I went out there and started training and training. Fans expect you to look like a real superhero, you can't just roll out of bed for this role."

When asked what was the most challenging part of the role, he added: "It was physically going into training and working out so much. I had never done anything like that and that was very very challenging."

And Ben admits he doesn't think the film would be so successful without his good friend Henry playing Superman.

Speaking of their close friendship, he shared: "He's great. I saw what he could do already in 'Man of Steel' and it was quite impressive.

"He's a pro and a great guy. He's a wonderful actor; I don't think we could have done it without him. He made it all that much better."