Tom Cruise had to work four times harder than usual on 'Knight and Day'.

The actor insists the action comedy required considerable skill and he and Cameron Diaz had to push themselves to make the film look fun but also dramatic.

He explained: "It requires a tremendous amount of skill. You have comedy, drama and action and it's very dynamic so it's actually four times the workload. Action movies are difficult and this has everything I love in movies. We did everything we could to make it non-stop, unpredictable fun."

The 48-year-old star also admitted he is often bemused by the speculation he hears about his career, but always tries to just focus on the project at hand.

He told the Daily Telegraph online: "I've heard so many things, going back to 'Top Gun' and 'Rain Man' and 'Born on the Fourth of July' - 'He's not going to make another movie', 'He's just a teen idol', 'It's going to destroy his career'. People are going to say whatever they're going to say. I've read it and seen it all before. That's just the way it is. What are you going to do?

"All I can think about is making the movie at hand and doing the best I can and enjoying it.