The old adage, “life is a marathon, not a sprint,” may spring to mind when watching writer/director Paul Downs Colaizzo’s debut, Brittany Runs a Marathon – based on the personal health journey of his best friend and former roommate.

Jillian Bell plays the eponymous and dysfunctional twentysomething who sets out to change her body (and life) by taking up running and eventually training for the New York City Marathon.

What starts out like an amusing “against all odds” story (a shot of the Rocky statue in Philadelphia features at one point) turns into more of an earnest dramedy. Colaizzo deconstructs the familiar transformational Hollywood concept and instills it with relatable and universal themes that focus on Brittany’s journey for self-acceptance rather than her get-fit regime.

Amongst all the drunken antics and meaningless sex, Brittany uses her quickfire humour as a defence-mechanism to hide her deep-seated social anxiety. This is a character that’s self-deprecating and flawed; constantly at odds with her mental and physical instabilities. To add authenticity, she’s also unlikeable and abrasive – particularly in one protracted scene that involves a fat-shaming meltdown.

A playwright by trade, Colaizzo certainly writes well, but the script has such a clear trajectory that there are far (and few) surprises leading up to its foreordained ending. There are also pacing issues, including a myriad of secondary characters that seem to clock in and out of the storyline.

Two such casualties are Michaela Watkins and Micah Stock, lending infrequent support as Brittany’s running partners with their own reasons for taking on the marathon. Utkarsh Ambudkar leaves a better impression as Brittany’s snarky love interest, Jern; creating some of the film’s best moments with his unconventional comic presence and amusing chemistry with Bell. There is also a neat turn from Get Out’s scene-stealer, Lil Rel Howery – playing against type as Brittany’s caring brother-in-law and surrogate father.

But the centerpiece is Jillian Bell, supplementing her character’s intrinsic humour and wit with pervasive flaws and authentic complexities. At one point, she talks about being the comic relief “sidekick”; an apt comment, considering her own string of supporting roles in films like 22 Jump Street, Rough Night and Goosebumps.

Though it may not motivate you to lace up your running shoes, Brittany Runs a Marathon is an introspective indie flick about self-love and empowerment; bestowing Bell with a lead role that’s worth a victory lap.