There's often a touch of the touching in the comedies of Brit Everyman Simon Pegg. "Shaun of the Dead" had his moments of sentiment, in between dispatching zombies.

But even knowing that, it's shocking how sweet his latest, "Run Fatboy Run," turns out to be. A less-than-outrageous romantic farce, it stops and takes the time to let us say, "Awwww," often at the expense of laughs.

Pegg plays Dennis, whom we meet in mid-panic attack on his wedding day. He's about to marry the stunning Libby (Thandie Newton). She's having his baby. It's going to be a big ceremony.

And all Dennis can do is run for his life.

What kind of knob leaves a woman who looks like Thandie Newton at the altar? Dennis must be London's biggest loser. That much is obvious when we jump forward five years to see the paunchy, chain-smoking security guard that Dennis has become.

But he's still in touch with the not-quite-ex because they have a son together. He'd love to worm his way back into her life. But she's taken up with the wealthy, charming American Whit (Hank Azaria), a hedge fund broker and athlete.

"He runs marathons!"

"Why?"

Eventually, this too-leisurely comedy gets down to its business, which is Dennis taking up the challenge of running a marathon with Whit. He must train. He must diet. He must finish because there are side bets that involve his back rent and his always-broke best mate, Gordon (scene-stealer Dylan Moran).

That's when this comedy, directed by "Friends" alum David Schwimmer, finds its footing. Training with the help of his funny landlord, Mr. G. (Harish Patel, just adorable), and Gordon, Dennis and Fat Boy start to sprint.

"You've never finished anything in your life," Libby insists dismissively.

Like most movies with a marathon in them, the race becomes the metaphor for a person finding inner resources that change his or her life. Schwimmer fills out his cast with a nice cross-section of British character actors, including "Little Britain" cross-dresser David Walliams. Schwimmer smartly withholds final judgment on Whit and marathoning and makes the real story about what Dennis must do to become a better man.

Pegg may not be the most convincing "fat boy," but he's on his game here, his expressive face contorted into pain, panic and prickliness. Azaria and Newton are basically straight-men to Pegg's shtick, which means two thirds of the movie isn't that funny.

It has meaning and sentiment and a nice payoff for its finale. But without more laughs, "Run Fatboy Run" is awfully winded by the time it crosses the finish line.