|Ryan Reynolds filming for 'Safe House' (upandcomers.net)|
The Canadian actor plays CIA agent Matt Weston in the forthcoming action thriller and was very involved in his character's stunts, despite movie bosses having hired a double for his more physical scenes.
He said: "I was fighting this guy for five hours and we're finishing it later.
"The fights in this movie are really long and extensive and they're ugly and there's biting and head-butting. Canadian Kung fu, we call it.
"I keep seeing a stunt guy dressed like me but they don't seem to want to put him in. I'm a wreck, but then I get to say, 'That's me getting my ass kicked by a 300lb mercenary'."
Ryan's co-star Denzel Washington has also been involved in some gruelling action scenes and while he has found some of the stunts tricky, he insists they haven't been too scary.
He told Empire magazine: "We haven't done a scene with a page of dialogue in a month. There's a lot of running and jumping in this film, and I've got a bad knee and I got waterboarded.
"Having someone pour water down your nose when you're upside-down is a bit difficult, although the guys doing it to me were more scared than I was I think."