NEW YORK (CBSNewYork) — For years, roller derby has walked the boundary of what’s perceived to be a normal sport.

But just because it’s not mainstream doesn’t mean it isn’t growing. In fact, it’s thriving with the emergence of a new generation, CBS2’s Steve Overmyer reports.

Among the warehouses in Brooklyn, behind the walls of graffiti, a classic sport is declaring a revival.

“When they hear about it, there’s just something that sparks in them, and they want to be crazy and do something on roller skates,” “Suzy Hotrod” said.

There are more than 100 roller derby leagues in America alone. But only one league is known worldwide: Gotham Girls Roller Derby.

“Suzy Hotrod” is one of the highest profile roller derby stars in the world. Today, she’s teaching a new generation. Twice a week, girls ages 8 to 18 come to the Brooklyn warehouse to become empowered.

“Going really fast on skates and kind of going a little crazy, and I also really like hitting people,” said “Malice In Wonderland.”

“It’s not a negative aspect to be strong and physical and confident, and a little bit sloppy and sweaty and smelly,” Hotrod said. “These are all things we celebrate rather than discourage.”

It’s a contact sport, and only one player per team can score. They’re called the jammer and identified by the star on her helmet. Every opposing player she laps, her team gets a point. But every lap comes with a battle.

“I love it. I think it’s incredible,” mother “Mid Wife Crisis” said. “With any sport you’re going to get hurt. Think about gymnasts, think about kids who are ice skating. It’s just as physical.”

“I think I’m a lot tougher,” “Hermione Danger” said. “Before I started derby, if I fell, I would probably cry or something. But now if I fall, I just kind of get back up and deal with it.”

Falling is worn as a badge of honor. Akin to life, it’s not how many times you fall, it’s how many times you get back up.

“Roller derby really builds a lot of confidence quickly,” Hotrod said. “You get knocked down over and over again, and the first thing you learn is to immediately get back up. A lot of lessons learned on the derby track that can make anybody a wonderful, stronger person.”

So far, two of the juniors have graduated to the adult league, but more are clearly on their way. One girl, named “Cookies ‘N Scream” told Overmyer she thinks 99 percent of her friends would love it if they tried it.

Their next bout is next Saturday at John Jay College.