avid Schwimmer – yes, the Friends alumni - makes his directing debut - with a British farce, no doubt. With the spasmodically amusing Run Fat Boy Run, Schwimmer is behind the cameras, while Simon Pegg (the offbeat star of Shaun of the Dead and Hot Fuzz) stars as Dennis, a born loser who competes for his ex and their five-year-old son's attention with her American lover in a marathon.

Dennis, whom we meet in mid-panic attack on his wedding day, is a man clumsily chasing after his dreams. Five years earlier, you see, the dumbass was about to marry the stunning Libby (gorgeous Thandie Newton). She was pregnant with his baby. It was going to be a big ceremony. And Dennis? He scrambles for the exit.

Time goes by, and now he's a paunchy watchman at a posh lingerie shop and living in a basement flat. He is barely making ends meet on his salary. He’s such a loser that little children give him the middle finger on the bus. Coming to the realization, in true rom-com fashion, that Libby is the one for him after all, he spends the rest of the film trying unsuccessfully to win her affections back. This is made more difficult by Libby's new significant other, rich, macho American businessman Whit (Hank Azaria).

Dennis wakes from his ever-say-die funk to announce that he will run in a London marathon against Whit, even though getting up the steps into his flat can be a challenge for him, pale, pudgy and puffing away on an endless chain of cigarettes. This is when Run, Fat Boy, Run finds its footing.