First of all, let me just say, as a reasonably fat guy, that Simon Pegg is not fat enough to be called “Fatboy”, as he is in the title of this movie. Run Fatboy Run makes the assumption that because Pegg is not in the ridiculously good shape of Hank Azaria that he must therefore be fat. Really, he’s just lazy and un-motivated. Not the same thing.
The idea here is that Pegg once left Thandie Newton at the altar while she was pregnant with his child. Which, again, stretches credibility. Leaving Thandie Newton? Anywhere? Let alone at the altar - seems unlikely to me. But that’s where we are. It is now a few years later, and he remains unmotivated and lazy, but loves his son. He meets his former lover’s new boyfriend (Azaria), who appears to be a kind, decent, perfect sort of superman. His perfection seems to be based almost entirely on the fact that he runs marathons - for charity! If that is the only criteria that is needed for perfection, it has become ridiculously easy to attain. I mean, Gandhi never ran marathons for charity! What a slacker.
Simon Pegg wants Thandie Newton back (understandably), and somehow comes to the amazing leap in logic that running a marathon for charity will enable him to achieve perfection as well, and therefore win her heart (not so understandably). So he begins to train for the marathon, where he will compete against her new flame. Suppose someone left you at the altar and gave no reason. And you hooked up with a fantastic new person who happens to be a great chef. And the old lover tries to win you back by cooking you a hot dog. Would this work on anyone?
Of course, because Simon Pegg wants Thandie Newton back, you know that the movie will have to end with Mr. Perfect out of the picture. And you know that the way to get Mr. Perfect out of the picture is to discover after a while that he isn’t, in fact, that perfect. And when that moment comes, it is so obvious, and so painfully ordinary, that you really wish that director David Schwimmer had put a little more effort in here. Or a lot more.
Because up until that moment, Run Fatboy Run is decent. It isn’t great, it has moments that are good, but by and large it’s decent, thanks mostly to Pegg’s great comedic timing and the antics of his best friends. Rarely laugh-out-loud funny, but it’ll do. Then when Azaria does that cartoon character thing that happens in all lousy romantic comedies, the movie comes crashing down. Why does the character that stands in the way of our hero’s happiness have to do something so cartoonishly EVIL all of a sudden, so his true colours can be seen?
Hank Azaria, at the one hour and twelve minute mark in the movie, may as well commit genocide, block out the sun, and beat the crap out of a schoolbus full of four year olds. Run Fatboy Run doesn’t quite go that far - arming him with grenade launchers and machetes so he can cut a swath of destruction - but it might as well. It’s a moment that really reinforces the point that this movie is exactly like every other cheesy romantic comedy. Only worse.