Getting in shape and putting your life together usually, at the movies, passes in a montage. But for many, the non-Rocky legions of us, such transformations require more than inspiring theme music and lifting weights in the snow. And for the Brittany (Jillian Bell) of “Brittany Runs a Marathon,” that’s especially true.

Brittany is an aimless and broke 20-something in New York who’s startled when her attempt to pry an Adderall prescription from a doctor (Patch Darragh) turns into a recommendation to improve her body mass index. He suggests she changes her hard-drinking lifestyle and lose about 50 pounds.

After a moment, Brittany gets over her initial offense and decides to go for a run. She starts with one city block. She eventually sets her sights on 26.2 miles. Along the way, she confronts her body image anxieties, makes new friends and turns into a young, professional adult.

The main reason to see “Brittany Runs a Marathon” is Bell. A former “Saturday Night Life” writer, she’s regularly been a bit player in comedies like “Office Christmas Party” and “22 Jump Street,” but this is her first lead role, and she’s stellar in it.

Get the the latest local entertainment news. Sign up for our weekly entertainment newsletter.

Load comments