The junior Derby Dolls don't stop for anything. Their arms slice through the air, demanding it make way for them as they whirl around the banked track, gaining speed with each lap. Neon pink, purple, green and blue helmets -- glittered with names such as Shark Bait, Skatey Perry and Sky ScrapeHer -- start to blur like watercolor paint as the girls, aged 7 to 17, fly by. "I feel cool because the wind's blowing in my face," says 9-year-old Scar Child, aka Leah Drazic. "I feel like I can do anything."

With Beyonce's "Run the World (Girls)" blasting throughout the Dollosseum -- a skate rink in El Sereno, just east of Downtown Los Angeles, that's decked out in black and pink and features a glitzy disco skate hanging from above -- the Black Widows and Pretty In Punk were warming up for a bout when I checked in on them back in September. The two teams are members of the junior league of the L.A. Derby Dolls, a roller derby organization established in 2003 that hosts a five-team adult league and a two-team juniors program. They skate nearly year-round, practicing with coaches during the week and engaging in "bouts," or 60 minutes of gameplay (four 15-minute quarters) on the weekends.

The junior Dolls have an elasticity to them, bouncing back no matter how brutal the bruise. "They all have some degree of fearlessness," says Vanna Fight, aka 33-year-old Andrea Acosta, a skater on the Tough Cookies of the adult league. "Even though they're much younger than me, I do find myself a lot of times thinking, 'I want to skate like them when I grow up.'"

For some of these skaters, roller derby is more than a sport -- it's family. Mothers in the adult program with daughters in the juniors practice skills together, joke around while putting on their skates, cheer for one another during bouts and cringe when their loved ones take an inevitable spill on the track.

Brewjita Supreme (aka Patricia Rodriguez) has two daughters in the juniors program, and says the sport brings them all closer together.

"I think that all little girls should participate in an activity, whether it be a sport or a community group or organization, that empowers them to empower other young girls," she says. "And anything that brings parents and children together -- especially mothers and daughters together -- I think is the ultimate responsibility of ours because it's going to forge a long-lasting relationship for a lifetime."

Here are a few of the Derby Dolls' family portraits, and the stories behind them.

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Known to the L.A. Derby Doll community as "Skullerdad," David Partida's signature clap during bouts can be heard almost anywhere on the track. He stands with Patricia Rodriguez and their daughters. Robert Beck for ESPN

Brewjita Supreme, 37, and daughters DOMOnator, 12, and Skullerfly, 10

A trip to Target for Rodriguez's family involves more than buying groceries or trying on clothes. While she scans an item, Rodriguez's two daughters Malinali Partida, who goes by DOMOnator, and Quilatzli Partida, aka Skullerfly, whiz by her on shoes that have built-in wheels. "Mommy, hip check!" they say, giggling, bumping her as if the aisle were a derby track. Other times, the two will practice blocking out by keeping the other from the closing elevator.

"That's what derby moms and daughters do," says Rodriguez, who has been skating for about two years. She encouraged her daughters to join the sport after her niece had taken it up. The girls were soon hooked, plastering posters and pins of the 2009 roller derby movie "Whip It" to the walls of their room. Eight months later, Rodriguez herself hit the track. She started off as part of the Dolls' "fresh meat" program, composed of new skaters over 18 who endure rigorous training before advancing to "subpool" (the pool of skaters teams have to sub in bouts). She now skates in Derby Por Vida, a Dolls-run recreational program that allows skaters to work on skills without competing on a team.

Malinali and Quilatzli often offer their mother advice: "Oh, Mommy, you know your snowplow?" they'll say, referring to a technique of stopping or slowing down in the sport. "You need to do it this way."

"My daughters are way better than I am," says Rodriguez, who is more concerned with the values the sport will teach her daughters, such as work ethic, competitive spirit and the ability to handle adversity.

"I like (derby) because it helps me show persistence, not giving up," says Quilatzli, wearing an orange helmet and a pink shirt that says "Feisty." "You have to get right back up and keep on going."

Rodriguez cherishes skating with her daughters because she had little time to engage in extra-curricular activities with her own mother. Growing up in a tough neighborhood in East Hollywood, she was bussed to the Valley for school while her parents worked six days a week.

Now, derby has brought her closer to her own daughters. "It's never a chore because if they're happy doing it, then I'm happy doing it," she says. "They love coming here."

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Kay'Lah and Shanquana Morgan practice together four days a week. Robert Beck for ESPN

Black Mom-Ba, 42, and Serena Killams, 10

Kay'Lah Morgan, who chose her skate name after the tennis star, often asks her mother to take her to practice early so she can perfect her snowplows. The pair spends four days a week practicing together. "It just builds our bond and makes our bond stronger," says Shanquana Morgan, who has risen out of the "fresh meat" program to "subpool."

When asked why she skates, Kay'Lah quickly points to her mom and smiles. "Because you do it!" she says. Morgan's motivation, however, is her daughter: "I knew I had to get better in what I did," she says. "I knew I had to not be a hypocrite and practice what I preach because I'm on the track telling her, 'Do this! Concentrate.' But am I actually demonstrating that when I'm on the track?"

Morgan has been enamored with roller derby since watching the Los Angeles Thunderbirds skate on television in the 1970s. Finding the physically demanding sport to be empowering at times, she wanted her daughter to gain strength from the track, too.

"When you look at it and you've never skated before, the track can be intimidating," Morgan says. "It's still intimidating to me to a certain extent, so I knew once Kay'Lah started and once she could see herself progressing, it would build her self-esteem and self-confidence. It's really liberating."

Morgan beams when remembering the first time her daughter skated last year, just lacing up her skates and zooming off with no experience. Kay'Lah wasn't afraid of making a mistake or falling. "She can be a little beast," Morgan recalls saying to herself.

Kay'Lah had to take some time off to recover from an eye injury, but her mother couldn't wait until her first bout. "I won't be able to contain myself seeing my baby out there," she says. "She's my little mini me."

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Roller derby has remained more than an outlet or a hobby to Rita Tapia and Lauren Mia Trivino; it has become a calling. Robert Beck for ESPN

SeñoRita, 35, and Shark Bait, 9

Lauren Mia Trivino isn't afraid to take on anybody, not even 17-year-olds twice her size. The 9-year-old who stands exactly, in her own words, "48 inches," often dashes through the pockets of air between bodies to jam to the front of the pack. As her name indicates, she's out for blood.

"She moves like a ninja in the night, and by the time you figure it out, she's scoring on you," a Derby Doll announcer said during the September juniors bout.

Lauren's mother, Rita Tapia, has been skating for about four years. The sport became her refuge during a difficult divorce, as she and Shark Bait moved from Santa Clarita to Whittier, California, for a fresh start. Tapia joined the Derby Dolls team Fight Crew, giving her new purpose and lifting her spirits.

"I needed something for me to do, to help me, to empower me, to give me confidence, to help me rebuild all that all over," she says. "I could be home, frustrated, and (my kids) are like, 'Go skate, Mom. You need to skate. Get out of here.' It takes a lot of my negative energy out."

Lauren has been a budding athlete since age 6, participating in karate, skateboarding, gymnastics, ballet and tap dance. But nothing stuck until her mother introduced her to derby.

"All the wind's in your face when you go really fast," she says of the part of the game she enjoys most.

SeñoRita took a brief hiatus from competitive derby in February because of increased demands at her job, but plans to return soon. It has remained more than an outlet or a hobby to the pair; it has become their calling. "We go to skate parks together," Tapia says. "We are both passionate about it. I mean, we love it."

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"She loves being a part of this place," Mary Drazic says of daughter, Leah. "She loves that she has a niche here." Robert Beck for ESPN

Lynn Cold Blood, 38, and Scar Child, 9

Mary Drazic and her daughter, Leah, enjoy the simple things about roller derby: sitting down and lacing up skates together, driving to the skate shop and discussing dazzling moves after practices and bouts.

"I like to see her skate because she can go really fast," Leah says of her mother, while wearing a blue helmet and tie dye knee-high socks. "She can do all the really cool moves. She can do what I can do, but moving faster and better."

Mary Drazic, a skater on Fight Crew who has been a bench coach for both Pretty In Punk and the Black Widows, taught her daughter the fundamentals of the sport (especially Leah's favorite: crossovers). But sometimes the roles are reversed. "She's knowledgeable about it and she'll tell me to do things in the game," Drazic says of her daughter. "I can tell her I did this awesome thing in scrimmage, or I got five points jamming, and she'll know exactly what that means and empathize."

Drazic took up the sport almost four years ago out of curiosity, after seeing a Derby Doll bumper sticker and later, a woman with a Derby Doll T-shirt. After her first day skating, she wanted to soak up everything she could about derby. Leah reacted similarly once she joined at age 7.

"She loves being a part of this place," Drazic says. "She loves that she has a niche here."

When asked why she loves the sport, Leah can hardly contain herself. "Because it's fun!" she says, stomping her feet while sitting on a bench after practice. A few minutes later, she returns to the track for more.