The It's Complicated star, who is married to Emily Blunt, played a real-life Navy SEAL in the tense action film and he took it upon himself to get ripped for the role.

"I did two-a-day work-outs with my trainer, Jason Walsh, who is a really great guy," he tells U.S. chat show host Jimmy Kimmel.

"I was like, 'Let's do it... Let's get the bench press going', and he'd say, 'No, you're gonna drag that sled from there to there...' I'm having a heart attack; it was so awful.

"My body fat was like 25 per cent... and he was like, 'That's awful...' and by the time I did the movie my body fat was nine per cent."