How fit are you out of ten?

It depends. When I was filming Death Race I was extremely fit but right now... If I was a ten then, I’m probably about a six or seven now.

What level martial artist are you?

Movie level.

You recently lost 17lb (7.7kg) in six weeks. What did you eat?

Not much. Mainly protein, nuts and berries. I was a miserable bastard.

You also trained with a former Navy SEAL. Why him?

He leads by example. You see people working out with some trainers and the trainers look like they need a trainer. It’s bizarre how they get the job if they’re not in fucking amazing shape themselves.

What did you do with him?

I trained six days a week, 35 minutes a day. We had two rules: we wouldn’t do the same workout twice and we’d record everything. The main part of the session would be intense and involve heavy compound lifts, circuits, kettlebells and medicine balls.

How long before a movie do you get into serious training?

Ten weeks is good. If you can do ten weeks you can make some real changes. Anything under six weeks you may as well forget about it.

What’s your top training tip?

Train early in the morning. Get out of bed and just do it. That way you’ll never find an excuse not to.

Where do you work out in Hollywood? Plush club or spit-and-sawdust gym?

I go to this place out near the airport in Los Angeles. It accommodates all these stuntmen. People who go there really train hard. It's great.

You finished 12th in the diving World Championships when you were younger. How did you get into the sport?

I just turned up one day and did it. I wanted to be a stuntman when I was a kid and it was a step in the right direction.

Who's your favourite action hero?

Bruce Lee. He’s the fucking real deal, you know? Most of the Asian action stars have been inspirational to me: Jet Li, Jackie Chan, Tony Jaa – they’re fucking great at what they do and it is them doing it. They impress me, not people who take credit for something they don’t do.

How would you fare against them in a fight? Chan’s getting on a bit, you could have him.

Poor old guy. To put himself through the mangle so many times in all those films, I'm amazed he can still walk properly. The thing about getting older is you don’t heal very well. When you’re 18 you tear a muscle and it heals quickly, but now it takes fucking months.

You spend most of your time in Hollywood now – is any of it rubbing off on you?