What do you get when you take an unfit, pint-swigging, British security guard and enter him in a 26.2 mile race for charity? Um, hilarity of course.

And that’s exactly what you’ll get in Run Fatboy Run, directed – surprisingly enough – by Friends’ David Schwimmer. When the less-than-driven, thirty-something Dennis Doyle (Shaun of the Dead’s Simon Pegg), meets the marathon running, go-get-em businessman dating Libby, the mother of his child (the one he’d left at the altar, pregnant, five years earlier), he vows to complete the Nike River Run, a 26-mile race through London – despite all the early morning runs, spandex shorts, and rashes in the “scrotal zone” that entails – all in an effort to win her back. He’s helped along the way by his chubby, smart-mouthed, landlord, Mr. Ghoshdashtidar, and his best friend, the often pants-less Gordon (Dylan Moran).

Movies of this type can all too easily become run-of-the-mill, but the writing in this movie pulls it out of the mire of predictability. The original story, meant to take place in Los Angeles, is the brainchild of Michael Ian Black, who should be best known for his work on MTV’s hilarious 90’s sketch comedy The State, but is – sadly – probably better known for his role as bowling alley employee Phil Stubbs on NBC’s Ed.

Once the film moved across the pond, Black teamed up with Pegg to write a more Brit-friendly screenplay, but Black’s random, somewhat slapstick humor still shines through in the moments when Dennis falls down the stairs at the gym, when a little boy in Lord of the Rings’ elf ears gives him the finger on the bus, and when Libby shows Gordon to the bathroom at her birthday party and he asks, “Hey, do you think it would be weird if I took a bath? [pause] Yeah, that would be weird.”

So despite the fact that you’ll know how it ends as soon as it begins, and you may find too many wrenches have been thrown into the plot, if you like irreverent, somewhat awkward humor, British accents, and Michael Ian Black, this is the movie for you.