LOUISVILLE, Ky. (WDRB) -- Once played only by adults, more and more kids are strapping on their skates for the bruising, fast-paced sport of roller derby.

Louisville kids are playing for the River City Juniors and they're learning more than just skating skills.

Eight-year old Rosie Miller suits up, lacing up her skates, strapping on her knee pads and fastening her helmet, to transform into "Thorny Rose." "It's kind of my secret identity," she said.

"Thorny Rose" is the alter-ego of this lean, mean roller derby queen. "The boys at my school are like wowed when I tell them I do this," said Miller.

Miller is one of the youngest members of the River City Junior Roller Derby team. While she might be tiny, she's not afraid to play rough. "You get used to the bruises and stuff," she said.

Once played exclusively by adults, the fast paced full-contact sport is attracting kids all over the country, including here in Louisville. 

Roller derby is played with two teams of five skating around a track. One player on each team serves as a jammer, and is identified as the one with the star on her helmet. It's her job to race around the track and score points without getting blocked by the other team. 

"Roller derby is one of the sports where girls get to prove that they're tough," said Amber Allen, who goes by "R2BeatU" on the rink.

On Sundays before Champs Rollerdome opens to the public, players race around the rink. Each player has a fierce and fearless name. It's just one way these athletes express who they are, a key part of roller derby.

"If you feel bad about yourself, you're more likely to feel better after practice, because you feel really strong after roller derby," said player Sarah Druly.

For many kids, this is a safe place where they can be themselves. 

"We have several that might have problems fitting in with their classmates at school, but they come here and they just naturally fit in," said coach Rebecca "Rexie Dangerfield" Thompson.

The league is so inclusive, it went co-ed this year. Two boys are now part of the team, like Blaise Saufnauer aka "GLITCH." "I just have to deal with it," said Saufnauer.

His mom plays roller derby and got him in the rink.

"If you know how to be hit, then you can hit," he said.

Throwing elbows and taking a fall are all part of the game these girls, and guys, love. It's a sport that teaches kids when you fall down, get back up and keep skating. 

The River City Juniors will host open enrollment for kids to join on January 29 and February 5.

Click here for more information.

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