Brittany Runs a Marathon gave actress Jillian Bell a huge opportunity: to play the lead character in a film that’s both funny and more dramatic than her usual fare. Bell is a familiar face from TV shows like Workaholics and Eastbound and Down, and movies including 22 Jump Street, Office Christmas Party, and Fist Fight.

But a leading role in a dramatic film was a new challenge. And it was made even more challenging because her character, Brittany, was taking on a huge challenge of her own: running a marathon. It’s part of Brittany’s larger realization that her life is spinning out of control, and her subsequent attempt to take back her life.

Brittany Runs a Marathon seems, at first, like a movie about a woman who loses weight and transforms her life. But while Brittany does end up losing some weight (it’s hard not to when you’re training for a marathon), this isn’t a film about having issues with your body. (As most runners can attest, successful running has very little to do with the number on the scale.) Brittany’s problems don’t stem from her body; they come from the belief she’s developed that life has passed her by, and it’s not really worth trying to change her job, her habits, or her toxic relationships. What needs a makeover is how she thinks about herself.

The resulting film, which premiered at the Sundance Film Festival in January, is a heartfelt and sometimes uncomfortable drama about the ways we try to save ourselves, how we sometimes hurt others, and why we need other people in order to grow. Brittany Runs a Marathon is writer and director Paul Downs Colaizzo’s feature debut, as well as a tribute to his friend Brittany, who did indeed run a marathon. And Bell’s performance is its heart and soul, leading a cast that features Michaela Watkins, Utkarsh Ambudkar, Lil Rel Howery, and Micah Stock. It leaves no doubt that Bell was more than up to the challenge.

I recently spoke with Bell in New York about her experiences making the film, how she approached the character of Brittany, and what she learned from running (some of) the New York City Marathon as part of the production. Our conversation, which has been edited and condensed, follows.

Alissa Wilkinson

How did you end up starring in a movie about running a marathon?

Jillian Bell

My manager sent me this script and said, “Definitely check this one out. It’s special. You might be nervous about the material, but I think it will make a beautiful film.”

So I read it. And I was terrified, because I’d have to be very vulnerable. But it was a role that I didn’t want anyone else to play, because I felt like some of these lines were taken from my own life. I related to the character so very much. I wanted to try and do her justice.

And it was quite an experience. I had a feeling it might be a little bit therapeutic, and it was.

Alissa Wilkinson

What was so scary — and so therapeutic — about it?

Jillian Bell

Some of the scariest parts were physical, and others were emotional. Physically, I decided to take the same journey [as Brittany], so I lost 40 pounds for the part. They didn’t ask me to do that, but I wanted to take it on because I felt like it would help me out with connecting to the character a little bit more. There were certain things throughout the script that I didn’t relate to when I read it, because I had never tried to train for something like this.

Some of the more emotional things that I was terrified about were just that it felt like someone had written parts of my life [into the screenplay]. I really related to the character. This is a very real, raw human story about this woman who is stuck in a place in her life and decides to make a big change. It’s so terrifying whenever you have to make that first step. I felt like Paul did such a great job writing this script, and I identified with it.

Alissa Wilkinson

That’s part of what makes it so relatable. Sometimes movies about women who transform their lives feel like fantasies — they have makeover montages, and you feel like you’re watching an Instagram influencer give you a pep talk. But Brittany feels very familiar to me, and the struggles she encounters are recognizable.

Jillian Bell

Right. I understand this person. There’s moments throughout where I feel like, oh, I’ve been that person, or I want to be that person.

It’s a totally different take on a “transformation” film. A lot of times, we see movies like this in which the lead character is thin, and then she loses more weight, and then her life is great. I was not interested in telling that type of story. And Paul didn’t write that story. He wrote a story where, even when her body starts to change, her life doesn’t get easier. She pushes away from people. There’s some real struggles.

I think that’s really smart to address — that sometimes, when you work on one aspect of your life, it doesn’t mean everything else catches up.

Alissa Wilkinson

It also has some montages where things change for her, which make you think you’re watching one of those more typical transformation films, and then it kind of pulls the rug out from under you. Normally, the transformation happens and then things are just better.

Jillian Bell

In other movies, the heroine starts wearing her hair down and gets a new outfit, and feels great. And that’s ... roll the credits. I’m like, what else happened to her? Is she mentally okay? What is she going through?

In this one, there were a lot of scenes in there where I’m like, oh, I don’t know if I’m rooting for her anymore. Then I get back on board somehow, because Paul wrote Brittany to be a real human being.

Alissa Wilkinson

I found myself thinking of The Devil Wears Prada, in which the main character kind of gets things together at work and in her own personal style, and another character says that when you start doing well at work, your life will start falling apart.

Jillian Bell

A lot of times, in movies, their problem was just one thing, and it’s usually related to their looks. So then we think that if they lose weight, they “get better.” I’m like, what? What is the message that sends to men and women? I don’t think it’s healthy. It’s a dangerous message. Life is pretty challenging and multilayered.

Alissa Wilkinson

So you said you decided to go through the same journey as Brittany does, running and transforming yourself and encountering those challenges along with her. What was that like for you?

Jillian Bell

I had a tough time. This was the first film I was involved in [at such an early stage], seven months before we started shooting, and by the time we were shooting, I felt like I’d shot it four times. I was like, oh, we’re finally really doing it.

Some of that was physical stuff and some of that was emotional stuff. They go hand-in-hand sometimes. A lot of the things Brittany went through that I couldn’t quite relate to [when I first read the screenplay], I finally understood.

I was scared. When you do projects that you know you’ll love, you know what you’re signing up for. With this movie, I couldn’t predict what it would be like. I had no idea if I would go in and fall flat on my face. If I would fail. I was extremely vulnerable, like an open wound walking around that set. If we didn’t have the cast and the crew that we had, who knows how it would have gone down. But I felt very supported.

Alissa Wilkinson

I guess that kind of support is not really the rule on movie sets.

Jillian Bell

Yeah. Sometimes they just want certain names attached, and not everyone is a wonderful, pleasant human being — I will say that.

For this, it was so great that everyone was as talented as they were wonderful. I felt like I was surrounded by all these angels, these very gifted angels who were always there to hang out or check in on me. I didn’t know how much I would need that. Part of me suspected that it would be a little difficult, that I might want to surround myself with people who were building me up, which is exactly what Brittany’s story is about.

It’s hard to ask for that. That is one thing Paul and I sat down and talked about. Most of the time, when you’re having creative conversations about casting, you’re just thinking about who’s the best actor. It turned out that the best actors for these roles were also the loveliest people. Which really worked out in my favor.

Alissa Wilkinson

And so much in Brittany’s story has to do with the friends she chooses and starts running with. They’re important to her transformation. In contrast, her roommate is an old friend, but she’s incredibly toxic once Brittany decides to start taking control of her own life.

Jillian Bell

Yes. And I think that a lot of times we don’t examine the friendships we have in our lives and how some of them are toxic — for me, it wasn’t until I was in my early 30s. Some friendships don’t fill you up. Sometimes you have to say, this is too draining, and I don’t think this person’s intentions are good. You have to end those at some point or another.

I think around Brittany’s age is when you start realizing, This person wants me to stay the same way. And that doesn’t make for a great journey throughout life. You want to continue to grow.

Alissa Wilkinson

Brittany’s relationship with her roommate is very revealing; sometimes people in your life are abrasive for reasons you don’t understand.

Jillian Bell

Whenever my friends come to me and say, oh, this person’s being so awful, I always like to say that everybody is living their own experience. For them, they’re the star of the show. There’s some people who will just sit with you while you need to talk and be there for you, maybe say nothing at all. And you can just feel that they want good things for you.

Then there are some people who will say lots of things, but they’re all the wrong things. I haven’t seen this depicted a lot in films.

Alissa Wilkinson

Friendship seems like a thing that films don’t often portray very well — in a movie like this, usually there’s a main character and then any of the friends are very two-dimensional and unimportant to the main character’s journey.

Jillian Bell

You’re right.

Alissa Wilkinson

I wonder if friendship isn’t as obvious a plot setup as romance for a film, because there’s no “destination” in a friendship the way there is in a romance.

Jillian Bell

There are some [friendship films] that are great. I really loved Booksmart. I really love Romy and Michele’s High School Reunion. But it’s not hit upon very often.

Alissa Wilkinson

Switching gears: In this movie, you had to shoot a marathon sequence, and you shot it during the actual New York City Marathon, right?

Jillian Bell

The real New York City Marathon! That day, I will never forget.

Alissa Wilkinson

What year was it?

Jillian Bell

2017. We couldn’t believe we got to shoot there. We got up at, like, 2:30 in the morning to get ready to go to Staten Island. The energy of that many people getting ready to do such a monumental thing — I can’t even describe it. I will forever hold that day in my memories. I just took in every moment of it, just watching these people who were achieving this huge accomplishment. I will never forget what it felt like to witness that.

Alissa Wilkinson

The marathon is a really special event in New York. People go out and watch and cheer for people they don’t really know, all these amateurs. It’s unlike any other sporting event.

Jillian Bell

Oh, yeah. People write their names on their shirts so others on the sidelines can cheer for them by name. The whole thing is emotional.

We had six people, including myself, for our crew that day. The guys who were running the Steadicam and the monitor and everything — they were openly weeping. We were just surrounded by motivational stories.

We were blown away by how many people wanted to support me. I think they thought we were shooting a documentary or something. It was very sweet.

Alissa Wilkinson

I used to live on a block on the race route, so we’d go buy a doughnut and a coffee and watch. You start thinking about the journey people go on to get to that race, which is exactly what this film is about: that journey. Both the journey to the race and the race itself are really more mental than physical.

Jillian Bell

You have to shut your brain off, in a way, and say, I got this. Even if I run a block now, my brain will be like, “That’s enough.”

Alissa Wilkinson

How far did you actually have to run for the movie?

Jillian Bell

I could get up to 3 miles, which isn’t a lot for runners, but it was a lot for me as someone who was just learning how to run. I did Couch to 5K.

Alissa Wilkinson

You’ve had months of interacting with audiences who’ve seen the film as it’s been playing at festivals. What do they say to you afterward?

Jillian Bell

People get very emotional! A lot of people approach us to say that it resonated with them, which is all you hope for. That really is one of the greatest compliments you can receive. That’s what I felt when I read the script, and that’s what Paul was hoping to have happen. So we feel really good.

With some people, we’ll have conversations about the film that are really interesting. Some people have a hard time seeing anything that relates to their own bodies and how they feel about their self-image. But I’ve had a lot of cool conversations come out of it.

There was this one woman who was sort of like, “So you lost weight doing this. Did you feel better?” And I was like, “No.” But that’s just me. I land somewhere kind of in the middle. I feel better about myself when I have a little bit more weight on my body. It’s where I’m comfortable. I don’t discriminate against people who are thin or bigger or whatever they enjoy. But you have to love your own body and the skin you’re in. And I’m like anyone else who has confident days and then not-so-confident days.

I think it’s an important conversation to have. Because I think that for years and years and years, we’ve seen films where women lose weight and then their life is wonderful and perfect. I’m not interested in seeing that kind of film anymore. It’s been done, and we’re not learning anything from it.

Alissa Wilkinson

And if you go to amateur races, you see people with all kinds of body shapes and sizes running simply because they like it.

Jillian Bell

Yeah. It’s about doing something they actually enjoy doing and they feel good after they’ve done it. And that comes in all shapes and sizes. That’s one of the movie’s themes.

Alissa Wilkinson

So did making the film motivate you to take on any challenges in the future?

Jillian Bell

The movie made me take on some things that I think I was very nervous about. It’s very scary to go out of your comfort zone, especially when a movie has more dramatic elements. I wasn’t sure how I would do, if I would like it, if I would fail. But I really love doing things that push the envelope a little bit and just make choices that are slightly nuanced, hopefully. That’s what I’d like to do.

Alissa Wilkinson

Do you have a dream role?

Jillian Bell

Yes. I’d love to play a witch. I want to play a witch more than I want anything in my life. I don’t care what kind of a witch. I love anything from Hocus Pocus to Witches of Eastwick to The Witch. Any kind of witch.

The good thing about playing a witch, though, is you can play it at any age. So it will happen. I just don’t know when.

Brittany Runs a Marathon opens in theaters on August 22.