Bruce Willis has admitted that it is tough being a middle-aged action hero.

The 52-year-old actor was at the UK premiere of his new ‘Die Hard’ movie - where after 12 years he is back in the role of wise-cracking cop John McClane for the fourth instalment of the franchise.

"I used to bounce off the concrete a lot easier than I do now," the actor, 52, said at the premiere.

"There were a couple of weeks where from my hip to my ankle I was black and blue. I got knocked out, I got some stitches. I wish I'd kept a scrapbook!

"The stuff I do with Maggie is just bananas," Willis told reporters on the red carpet.

"You would think I would be able to kick that girl's ass but not so much. I caught a beating."

US film-maker Len Wiseman, who previously worked on the ‘Underworld’ movies, directed the latest Die Hard instalment which is released here on 6 July.