PARK CITY – Brittany (Jillian Bell) is 28-years-old, lives in New York City and in a rut. Her best friend and roommate, Gretchen (Alice Lee, good), is self-obsessed with her social media standing and has little interest in Brittany unless they party all week long. Her advertising jingle career has stalled and she now gets by as an usher at a small Off-Broadway theater.  She can find a way to make a funny joke about any situation though and on the surface, it looks like she has her shit together. In reality, it’s a much more complex situation and that’s arguably the most fascinating aspect of writer and director Paul Downs Colaizzo‘s feature debut, “Brittany Runs A Marathon.”

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Acquired by Amazon Studios for a hefty sum after its world premiere at the 2019 Sundance Film Festival, the film’s premise is based on events that happened to a real Brittany in Colaizzo’s life.  The starting line for the big screen Brittany is a visit to her doctor office where he informs her that her body mass index is in the obese zone and she has high blood pressure.  She needs to start exercising and try to lose some weight or she’ll seriously be risking her long term health.  Startled by the news, she visits a local gym but discovers she can’t even afford the lowest monthly fee that allows you access to just half the facility (a fun bit with “SNL’s” Mikey Day).  Instead, she ends up getting inspired by her upstairs neighbor, Catherine (Michaela Watkins, fantastic), and ventures to try a more economically friendly form of exercise, running. Bell and Colaizzo have a lot of fun with Brittany barely making it down the block on her first time out, but happily, don’t dwell on her difficulties.  She’s soon doing her best to run every day and make changes in her eating routine.  When the slightly intrusive Catherine (who Brittany and Gretchen have mocked for years) suggests she join her Saturday running group she initially scoffs at the idea only to sheepishly show up anyway. On her first run, she bonds with Seth (Micah Stock, so good) who is also not a natural runner (his admission that he’s only getting in better shape because his four-year-old daughter was mocking his athleticism is one of the funniest moments in the movie).

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Over the months that follow, Brittany, Seth and Catherine all decide to train for the NYC Marathon and form an eclectic buddy group our heroine takes a little bit for granted. More importantly, Brittany’s exercise and abstaining from partying (much to Gretchen’s dismay) is working. She loses a ton of weight and actually starts to feel good about herself. Her next problem is that running in the Marathon ain’t cheap and she simply can’t afford it on her salary. That’s when she lucks out becoming a house/dog sitter for Manhattan’s 1% (honestly, everyone might want this gig).

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When she shows up to a sweet brownstone for her first assignment she discovers the obnoxious nighttime sitter, Jern (Utkarsh Ambudkar, more please), has basically moved in for the duration of the job. They bicker and roll their eyes at each other, but you know they’ll end up in bed together long before they ever do.  It’s one of the more predictable aspects of a screenplay that surprises more in its dialogue and nuance than its plotline.

Even after Brittany gets a major injury you can still see where this feel-good story is going.  Where it surprises is in Bell’s fantastic performance and the fact it eventually stops becoming a laugh out loud comedy.  It soon dives into much more of a heartwarming drama with a few random jokes thrown in.  Things are tough for Brittany.  She hits a bunch of roadblocks and Colaizzo isn’t afraid to get real and get real quickly.  Brittany’s arc isn’t just about getting healthier, but battling the self-hate she’s hidden for years.  If that sounds jarring, it actually isn’t.  Bell also doesn’t have carry “Brittany” all by herself.  The chemistry she has with Ambudkar is genuine and having Lil Rel Howery pop up every so often as Brittany’s tough loving, but supportive brother in law allows for some comedy relief when things get more slightly more serious.

Listen, Colaizzo isn’t breaking the mold here.  The movie looks like every indie pseudo-romantic comedy this century (and about four other films set in New York at the festival).  Unlike many of those, however, “Brittany” has Bell in the spotlight and that’s more than enough for a great finish. [B]

“Brittany Runs A Marathon” should hit theaters later this year.

Check out all our coverage from the 2019 Sundance Film Festival here.