‘Brittany Runs a Marathon” is a crowd-pleaser that earns its runner’s high step by sometimes awkward step. A New York City empowerment fable, it’s based on the experiences of a party-hearty friend of writer-director Paul Downs Colaizzo — she pops up under the end credits — who got her health back and life together by setting out one hungover morning for a run.

Thankfully, the movie approaches this subject the way one might a used car, with suspicion and an extra helping of mordant humor. It just folds in the endorphins gradually, until you understand why audiences voted it their favorite film at this year’s Sundance Film Festival.


It matters, too, that the movie’s Brittany is played by Jillian Bell, a comic actress best known for the Comedy Central series “Workaholics” and for stealing a good portion of “22 Jump Street” from Jonah Hill and Channing Tatum. Bell’s character here is best positioned as a toned-down indie-movie version of an Amy Schumer heroine: a generous body coupled with ungenerous self-esteem that has dead-ended her life in lousy choices and lousier men. It doesn’t help that Brittany’s nearing 30 and her roommate, Gretchen (Alice Lee, doing what she can with a shallow role), is a rail-thin social media “influencer” whose Instagram feed would make Gwyneth Paltrow turn green.

A visit to a doctor to score Adderal results instead in an ultimatum: Live whatever life you want, but if you want to live it longer, get some damn exercise. A NYC gym membership proving too much for her budget, Brittany sets a very tentative foot on the sidewalk outside her apartment door. “Just one block,” she mutters. Cue the “Vertigo” camera effects.

“Brittany Runs a Marathon” mostly sidesteps the easy jokes in favor of human-based character comedy. If the fat-suit and extra layers of latex don’t quite convince in the early scenes, Bell’s caustic wit and the pilot flame of hope in Brittany’s eyes keep a viewer invested. Gradually the movie introduces compatriots: Catherine (Michaela Watkins, excellent), a neighbor and experienced runner whose Mrs. Perfect exterior hides a messed-up past and present; Seth (Micah Stock), just as hapless at jogging as Brittany but urged on by his husband and sons; Brittany’s sister (Kate Arrington) and brother-in-law (Lil Rel Howery), cheering her on from Philadelphia. (Yes, there’s a shot of the Rocky Balboa statue.)


With the appearance of Jern (Utkarsh Ambudkar), a profoundly sarcastic slacker who crashes Brittany’s dog-sitting gig at a Fifth Avenue townhouse, the movie delivers a foil who slowly turns into a believable and welcome romantic interest. Like its heroine, “Brittany Runs a Marathon” works its way up from the easy comic 2Ks to a more nuanced drama of self-confidence that’s able to go the distance.

There are detours along the way. Colaizzo hews to the screenwriting dictum that a third act must introduce setbacks and disappointments to be reckoned with in time for the finale, but those setbacks feel forced on Brittany rather than organic to her story (plus they make the movie feel overlong). On the other hand, the heroine needs to sweat out her psychological toxins along with everything else, and the last half hour gives a lovely monologue to a minor character, played by Sarah Bolt, who provides counterpoint to Brittany’s war with her self-image.

That such a war is winnable may be the most cheering aspect of “Brittany Runs a Marathon,” anchored as the movie is by Bell’s down-to-earth millennial distrust of anything and everything meant to be Good For You. Plus, it’s New York — things aren’t supposed to work out, or work at all. Until you give a little push, and they do. Anyway, it’s just one block.


★ ★ ★


Written and directed by Paul Downs Colaizzo. Starring Jillian Bell, Michaela Watkins, Utkarsh Ambudkar. At Boston Common, Kendall Square, Coolidge Corner. 104 minutes. R (language throughout, sexuality, some drug material).

Ty Burr can be reached at ty.burr@globe.com. Follow him on Twitter @tyburr.