After a three-hour roller derby practice, 30-year-old Kat Pihl kicks off her skates. She says the sport has changed the way she feels about herself — particularly in relation to an eating disorder she’s had for most of her life.

“It’s one of those things you never really grow out of,” she said. “It was a lot worse for many years."

But since she started playing roller derby, Pihl said, she has gained weight and feels better.

“I always wanted to be smaller, but now I want to be stronger,” she said. “That was a mental change.”

Pihl is part of the Worcester Roller Derby league (WoRD), which meets every week to train and practice at the Habitat for Sport Complex, 20 minutes outside the city.

Aside from being a source of regular exercise and community, Pihl and her teammates say the sport has changed the way they feel about their bodies and how they move through the world.

Roller derby leagues have been gaining in popularity in cities around the U.S. and worldwide. The Women's Flat Track Derby Association (WFTDA) represented 20 leagues in 2006, it said, and now represents 463 leagues across six continents. There are seven active WFTDA leagues across Massachusetts representing western and central Massachusetts, Boston, the South Coast and Cape Cod.

Kimberly Eisen, marketing and communications director for the Women’s Flat Track Derby Association (WFTDA) in Austin, Texas, said more women are getting into roller derby partly because of its culture.

“Roller derby gives permission to something that women traditionally don’t have permission for,” she said. “Take up space, be loud, be aggressive and be yourself.”

The Worcester Roller Derby league.
Anna Kusmer WGBH News

To the untrained eye, flat track roller derby looks like a brawl on skates, but it’s actually a complex and strategic game. Two teams of five skate counter-clockwise around a flat, oval track painted on a gym floor. Each team has a special player, called the jammer, who tries to make laps around the other team’s players. Both teams try to stop the other team’s jammer while simultaneously trying to help their jammer make laps. All skaters are playing offense and defense at the same time.

The sport is intense and athletic, but it’s also colorful and full of quirks. Each player in the Worcester Roller Derby league has a “derby name” — a nickname they give themselves that usually involves a pun. Pihl is “Wildish Jambino.”

The league’s team names are no exception, and are a nod to their Worcester roots. The A team is The Triple Deck-Hers, named after Worcester’s iconic triple-decker homes, and the B team is called the Hurt of the Commonwealth, a play on Worcester’s city motto, “The Heart of the Commonwealth.”

The Worcester league is a colorful crowd. Players sport a variety of tattoos, piercings, brightly-colored spandex, shoelaces and helmets.

And no single body type prevails. Players are small, big, tall, short, thick and thin. Pihl says one of her favorite things about the sport is that whatever shape you are, you’re useful on the track.

If you’re big, you can block or push people aside. If you’re small, you can weave around other players. Players say beyond changing the way they feel about their body’s size and shape, roller derby has helped them feel better about taking up space.

“Growing up, being big, you take up space, and you want to be as tiny as possible all the time,” said Samantha Woodworth, who goes by Nancy Drew Blood. “But in derby, that’s an advantage. If I can take up space, I can take up more room and stop people.”

Allison Taggart, who calls herself Alysin WonderSlam, said the sport changed the way she feels about her body.

“I always struggled with how big I was, I was too skinny or not skinny enough,” she said. “Now, I want to build muscle. I want to be bigger, I want to wreck people.”

Taking up space is a literal concept: not feeling sorry about bumping up against people on a crowded bus.

“I bring that with me on to the elevator, too,” said Jessica Potts. “Like, you don’t get to push me into the corner, I play roller derby.”

The Worcester Roller Derby league.
Anna Kusmer WGBH News

Taking up space is also a figurative concept. It can take the form of asking for what you want or expressing anger.

Eisen said the sport got a popularity boost after the reality T.V. show "Rollergirls" aired on A&E in 2006, and again in 2009 when the movie "Whip It" came out.

The nicknames are an homage to roller derby culture of the 1940s and ‘50s, said Eisen, when the sport was more theatrical and staged than it is today.

“It’s a nod to times gone by,” she said. “But also very culturally important to the sport.”

Eisen said the names are sort of alter-egos on the track, but after a while, your "derby persona" and your outside life meld together.

“The two worlds sort of mesh,” she said. “It’s sort of an idealized version of yourself, but it very quickly becomes exactly who you are.”

Pihl said roller derby isn’t her first time playing sports, but it is the the first time she’s ever felt passionate about a sport and connected to the other players.

“This is the first time I’ve committed to a team,” she said. “I want us to improve as a team.”

Pihl helped re-grow the league after it nearly dissolved in 2016. Throughout the practice and during breaks, she explained rules to other players and offered tips.

Right now, both Worcester teams lose pretty much all their games. but that’s okay, the women said — they have nowhere to go but up.

“We’re underdogs,” said Pihl, “but someday, we won’t be.”