Seven months of sweaty, muscle-straining seven-hour days, and the guy who specialized in daft, oafish sidekicks in films from "Shawn of the Dead" to last year's "The World's End," a man who "always fancied myself a dancer," had his "big, old-fashioned dance musical." "Cuban Fury" let him kick up his heels, battle the office heel (Chris O'Dowd) for the hand of the lovely lady (Rashida Jones) and get the girl, as they say.

Frost, 42, best-known for his films with his best friend, Simon Pegg ("Hot Fuzz," "Paul"), is part of a long comic tradition of graceful big men — a round mound of twinkle-toed clown in the Zero Mostel, John Belushi and Chris Farley mold. Dancing comes naturally to guys like that.

"The problem, as it is with most blokes and dancing, is GETTING you to do it," he says. "If I'm expected to dance, I can't. But if you leave me alone with some Stella Artois and some tunes, I'm dancing. Dance happens."

His prep work took him into London's Latin community salsa underground, where he got his training and cast all the extras for the big dance competition scenes.

He talked Ian McShane (as his character's dance guru) and O'Dowd, Jones and British funny woman Olivia Colman (as his sister) into joining him in his quest.

"They didn't realize it was a full-on dancing movie when they signed on." He dealt with his own trepidations about strutting his stuff in front of experts.

"The finale ... every extra in the scene was a great dancer, the whole London salsa community. Some of Europe's best dancers were there ... Three times during that week of shooting I had to find Morag (Webster),our unit nurse. You know, slip off and find her and kind of casually say, 'Hey Morag, can I see you for a moment?' Panic attacks. Terrible nerves about doing this complex choreography in front of people who will KNOW if I mess up."

But he made it. The movie goes into limited release today. April 11 and wider release April 18 in the United States. It earned mixed reviews in the UK, and grudging respect for Frost's moves, with Quickflix noting that "Nick Frost's ideas may not be all that original, but he knows when he's got a good one."

Frost figures it has to do with the dancing, and that famed reserve of the British male — Keep calm, and whatever you do, don't dance.

"We just don't dance with girls. We don't. We dance AT them or near them. Maybe, at the end of the night, when you've had a few drinks and she's had a few more, she might dance in front of you. And you think 'YES! This is IT!'

"Miami or Manchester, it's the same all over the English-speaking world. We segregate ourselves, sexually, which is why when you're a man who can dance, it's such an attractive thing to a woman. It shows you don't care who sees you. You're confident as you're literally shaking your tail feather."