They sprint from the parking lot toward the doors of Urban Active, juggling gym bags, water bottles and one last text. Impatient with the slow-moving check-in at the front desk, they know there are only seconds to spare. After that, they're relegated to the back row or, worse, the dreaded sides of the room. These young professionals, stay-at-home moms, empty nesters, dance pros and teenagers in braces all are jockeying for a prime spot at one of the hottest tickets in the world of exercise classes: the Friday night hip-hop session with Michael Nicholson.

When the music starts, Nicholson winds through the rows-chatting, joking, prodding and dancing one-on-one. He embellishes the choreography with a double spin or a soaring jump. Regardless of ability, everyone throws down major moves in a sweat-soaked, heart-pounding hour. And they burn anywhere from 500 to 1,500 calories. "He pushes us to the max," says Angie Franklin. "There's no one like him."

Nicholson is a superstar at Urban Active Polaris, attracting big crowds even during a rush-hour time slot on a date night-as well as at Life Time Fitness in Dublin, where he draws between 200 and 300 people per class.

He joins a handful of dance fitness instructors around town-such as Pamela Conn, Kenya Day and Patrice Doran-who have the outsized talent and infectious charisma to command this kind of following.

All have their own styles. Besides Nicholson's urban hip-hop, there's Conn's high-energy Zumba with a You-Can-Do-It! attitude; Day's exotic Zumba, laced with belly-dancer hip drops and suggestive shimmies, and Doran's street jazz and hip-hop hybrid. And while they're certified as instructors, most of their dance ability, they admit, is self-taught or simply innate. Only Nicholson has had formal training (tap and jazz). But it makes no difference to the crowds that flock to these classes.

They just want to move.

On a recent Friday night at Urban Active, Nicholson saunters in promptly at 5:45 pm acting mellow and relaxed while scrolling through his iPod. "Good mornin' everyone," he says in a slow drawl. Morning? Is this 34-year-old from Brooklyn-tall and impossibly ripped, with dreads, a do-rag and swagger to spare-rocking a night-for-day lifestyle? In Columbus? For that moment, it seems possible as the class kicks off to V.I.C.'s "Wobble," a spicy show-me-what-you-got line dance that conjures images of late-night clubbing, close-contact booty shaking and a last call round of drinks.

With Usher, T-Pain and Ludacris, the pace picks up considerably. After about 30 minutes, the floor is clearing after each song-water bottles tipped back and drained. Nicholson voices his signature concern, "Y'all aw right?" (Spoken with a grin and a slight chuckle.)

It signals escalation. Lil Jon's "Get Outta Your Mind" must be coming up, with crunches and runs and those big jazz slides. The class groans.

There's always encouragement-"C'mon! C'mon, now!"-from the unofficial party motivator, David Franklin, who dances in the front line with full-throttle intensity. A national clogging champion at age 10, he moves as though he's hinged. Core control, it's called, as Franklin glides and krumps, waving and locking.

For one professional dancer, it's the hip-hop genre itself that's challenging. Cassia Hinchman-a ballet instructor and director of Seven, a contemporary dance company-loves Nicholson's workout. "But that lower, loose hip-hop posture is difficult," she says. "Ballet is the opposite-upright, controlled."

Nicholson's choreography, despite its cool factor, is strategic. "I make sure to vary the intensity," he says. "And work the different muscle groups-abs, glutes, quads. I've even thrown in some plyometrics for explosive muscle power." High knee lifts, chorus line kicks and scissor-arms-to-the-point-of-exhaustion will get results.

It's inspiring for Olivia Watson, an 11th-grader and varsity cheerleader at Worthington Christian High School, who dropped her ballet study two years ago. "He's rekindled my passion for dance," she exclaims. "I'm hoping to minor in it in college."

As for that hard-partying mystique of Nicholson's, it's hardly the case. Take his teaching schedule, for one thing. Ten classes per week all over town: morning, night and in between. He's instructing at the two gyms and renting space for hip-hop classes at AmeriCheer in Westerville and the Columbus Dance Centre in Gahanna, where he says he had more than 1,500 participants express interest in joining.

He also maintains a graphic design business, but as of late has pursued fewer clients. Plus, Nicholson's a dad. His face warms as he talks of his 5-year-old son, Skyler, who's already busting moves. "He loves to dance and says to me, 'Daddy, I'll teach you how to Dougie.' " And then there are Sundays, which are given over to music-Nicholson is the choir director at New Salem Missionary Baptist Church.

About a year ago, during a soul-searching moment, he considered giving up hip-hop instruction to grow his graphic design business or get what he calls a regular job. "That very day a woman came up to me after class," he says. "She started crying, right there in the gym. She had been depressed, going through a tough time when a friend had told her about my class. She became a regular, at four times a week."

Nicholson pauses. "She said to me, 'You saved my life.' " He looks away. "That's powerful stuff. Helping people like that, almost a ministry."

Maybe it's an ectomorphic thing. You know, where you're just born into a body that's strung together with long, thin muscles and stays forever skinny no matter what.

Although 44, Patrice Doran looks like a kid just out of her teens in tightly fitting olive drab cargo pants, white Aero underwear band riding up in back (so street!), purple cropped camisole layered over a black running bra and a snug wine-colored cardigan that comes off after the first dance.

It stretches the mind even further to know she's a mother of five (oldest 16, youngest 4). If you hadn't seen her pregnant, you might assume she adopted her brood and lied up her age. Her taut, tan body and long, model-slender legs have none of the typical landmarks of motherhood or maturity.

She's been teaching dance since she was 18. Younger than that, actually, if you count the $2 per head she charged at age 10 for hip-hop lessons in the basement of her childhood home in Seekonk, Massachusetts. "My parents had installed a mirror down there and I was always dancing. There were three little friends who came for lessons," she says with a laugh. "Six whole dollars! I thought I was rich."

Doran sourced her early moves locally. A neighborhood gal, Brenda, four years wiser and hot stuff as Miss PeeWee Rhode Island, taught Doran all she knew. Swivels, spins, the kick-ball-change and even some pageant-walking were locked forever in Doran's muscle memory.

After high school, Doran began teaching at a Bally's in Rhode Island, just over the Massachusetts line. Many years, relocations and kids later, she again tapped into her passion for dance by starting a class called Cardio-Jam at New Albany Country Club and the Westerville Athletic Club until it closed. Gold's Gym (now Urban Active) immediately snatched her up and a big crowd went with her.

She's currently teaching Cardio-Jam at Diamond Dance & Fitness in Gahanna and dance classes at Urban Active Polaris twice a week, and she conducts her own small group training at New Albany's Ultimate U. Like many fitness instructors, she has to string together gigs.

"I'll be honest," Doran says. "It'd be exhausting to make a living from this and I'm lucky I don't have to. You have to be there mentally. Be up."

At some point, she may return to school to pursue a degree in obstetric nursing. "I'd like to work with moms-I've been a doula for nine years. The whole birth process is such a wonderful thing."

But for now, she dances. It's a stress reliever, she says. "For that one hour, I get away from the kids, and then I'm OK with anything else." And it's fun, "like dancing with friends."

Chris Bell would agree. The accountant and father of two daughters is so committed he uses vacation time to attend Doran's Tuesday morning class. "It's a great workout," he says. Initially, he had wandered in by mistake, searching for cardio. "When I realized Cardio-Jam was dance, I would've left, but didn't want to make a scene," he recalls, laughing. Often, he's the only guy in the class. "That's awkward at first, but guys, stick with it," he advises. "No one is looking at you."

Custom-blended choreography is Doran's trademark. "It's jazzy at times, with funk and hip-hop. And some ballet thrown in," she explains. Pulsing to the dance house techno-beat of J. Lo and Pitbull's "On the Floor," one of her opening numbers, Doran combines smooth body rolls with the staccato of chest pops. She flies across the room doing a gliding ballet move that dissolves into quick pivots.

"Most of the steps are an eight-count combo, so it's pretty easy to follow," she continues. "When the music changes, you'll hear it. That's when I add something new."

That creative process is something her husband, Jeff, finds amusing. "I come up with these things when I'm in the kitchen cooking dinner," she says, laughing. "He gives me a hard time, goofs on me."

She'll lift a move from almost anywhere. From a choreographer: "Chris Urteaga's out in San Diego. He's amazing. YouTube him." Or from a 13-year-old girl. "My girlfriend's daughter Kyla will come over, and if I'm stuck with something, she'll say, 'Oh, try this.' Kyla studies modern dance. She's fabulous."

Or she'll recycle those Brenda moves she did as a kid.

Exuberance. Pamela Conn sure has it. It spills over in her speech, still tinted with inflections from her native Ecuador. And in her walk or the way she unloads armfuls of Zumba equipment from the back of her SUV. Even in her smile and how she greets the early morning arrivals at Diamond Dance & Fitness in Westerville: "Are you ready? Are you ready to move? Let's go!"

That same exuberance is infused start-to-finish in each of her Zumba classes, whether it's strictly dance or one mixed with weights and toning exercises or Zumbatomic for little kids. "She's got amazing energy," says Anna Kuhn, a mother of two small children.

Created by Colombian fitness instructor Alberto Perez more than a decade ago, Zumba is a Latin-based dance-party workout that continues to explode in popularity. Check the schedule of almost any major gym in Columbus and it's listed. Licensed Zumba instructors such as Conn pay a membership fee to receive copyrighted music and choreography monthly, then mix in their own downloads and signature moves.

As Pitbull's "Give Me Everything" thuds on the massive sound system, Conn, in floral turquoise-and-blue Zumba-issue cargo pants and a tight black tank, warms up the class-her dark, curly hair whipping side to side. It's classic Zumba: four basic steps that repeat. "With that choreography, even someone who's never taken a class can feel successful," she later explains.

Conn came to the U.S. as an exchange student her senior year of high school. Her host family in Ithaca, Michigan, had a son five years older than Conn, and he had a best friend, Jason, whom Conn adored. So much so, they eventually married. Sixteen years and two kids later, she's found her way from a retail career at Victoria's Secret to account executive at Sunny 95 radio to fitness instructor. That last one was pretty much by accident.

"My husband had given me a gym membership to Life Time Fitness back in 1998," Conn, 36, recalls. "I was mad at him for buying something we didn't need." But she began attending Jeanne Caliguiri's Latin fusion class. And despite the lack of dance training-"We didn't have the means for lessons when I was growing up"-Conn was a natural.

"My soul woke up," she exclaims. "After four months, Jeanne suggested I look into teaching."

There was one little problem. Conn is dyslexic. "I can't tell my right from my left," she admits. "It's crazy, I know. But I don't dance with my mind, just my heart. Music moves me. And I realized that if I can dance, anyone can."

That's become Conn's philosophy, and it's an attractive one to her followers. She went from teaching at Urban Active Polaris 18 months ago to becoming part-owner of Diamond Dance & Fitness, where she offers Zumba multiple times a week.

Conn and her business partners, Alexander Thomas, a top-20 U.S. ballroom dancer, and Daniel Hamilton, a Fit Life personal trainer, recently opened a second Diamond Dance & Fitness, in Gahanna, with plans for two more Columbus locations. Becoming a franchise also is a possibility.

"For the body and the soul, for your health, you need to do something beautiful. When we're here together dancing, everything is all right for these moments," she says. To further connect, Conn's starting a blog for class members. "I've had people tell me, 'I lost five pounds,' or 'I've been able to get off my blood pressure medication.' It's inspiring. It will create a community."

Before the hour is out, Conn has blasted through the merengue, a steamy salsa number, a hard-hitting rock-and-roll anthem, reggaeton, the Colombian cumbia and a few hip-hop moves for good measure. Target zones: the core, shoulders, quads and hamstrings. For first timers, she reminds them that in two or three sessions, they'll have it down totally.

And then she calls the class to attention once more. "I want you to remember this," she says earnestly, as she looks from student to student. "Dance like nobody is watching." The room goes silent. "And love like it's never going to hurt."

In the large mirrored studio, dark but for a few low lights trained toward the stage, it starts to feels like girls' night out for 100, minus bar food and Appletinis. Oh sure, guys are welcome, but they tend to hang just beyond the glass wall, out there in the gym, some pretending not to watch, others gaping, as the fireworks begin.

Kenya Day, 39, a sexy, sizzling bombshell, is cranking up the heat in her Monday night Zumba class at Dublin's Life Time Fitness. In short shorts, a tight orange tee and gold lamé high-tops, she laughs as she cues the first track.

"OK, most of you are not going to know this one. It's old school," she calls out, as Tina Turner's "Proud Mary" starts easy, finishes rough. But it inspires a seductive prance, a rapid-fire jazz square and Day's trademark move, the drop-down, shake-your-booty step that tones everything God gave you, all at once.

Can't quite get it? Regardless of age, size or dance experience, Day says just be yourself. "You should move however you feel comfortable. This music is so full of passion. It gives you the confidence to feel very sexy as you dance."

"We feel safe in here, nobody's judging you," says Havilah Stansbery, a lab technician who's been studying with Day for 18 months.

Whether riding the infectious beat of T-Pain's "Booty Work" or body-rolling in reggae and hip-hop drops to "Prrrum" by Cosculluela, Day shakes it hard. Shakes it like Shakira, the Colombian singer whose smash hit, "Hips Don't Lie," put belly-dancing on the Gen-Y radar. And with Day's long, wavy blonde-streaked hair and soulful brown eyes, they even look alike. But despite her mastery of rapid-fire hip thrusts, rib-cage isolations, shimmies and undulations, Day has never taken so much as a single belly-dancing lesson.

"I just feel the music way down in my soul," she says. The Columbus native, who's been teaching Zumba for nearly three years, grew up moving to the beat. "With three sisters and a brother, there was always something playing-R & B, hip-hop," Day recalls.

A hairstylist by trade, Day only recently has made the shift to full-time fitness instructor. In addition to Zumba, she's into Pilates. "It complements a dancer's body, adds strength and flexibility," she says, adding she's begun teaching at the Pilates Studio of Bexley.

Day keeps inventing ways to motivate her students. "I desperately want them to reach their fitness goals," she says. "Because when they feel their best, it's life-changing."

These four popular instructors say they're not in it for the cash, but for the satisfaction of helping others and dancing itself. From a management perspective, you hope that's enough to keep them on. And while program directors continue to embrace hip-hop, Cardio-Jam and iterations of Zumba-all rolling successes-they're still scouting for new ideas. And the next fabulous instructor.

Life Time's national director of group fitness programming, Kimberly Spreen, would bet on-ready for this?-ballet. "Ballet's been big in the larger cities. Life Time's slated it for the Columbus market in 2012," states Spreen. "And we're introducing Warrior Fusion, combining dance-like rhythmic movement and yoga."

For the 18-and-over female set, Urban Active Polaris will be reintroducing Urbanesque, a cardio-striptease dance class. "You don't actually strip," explains fitness director Angi Orders, "but it does involve sexy music, hair tossing and a chair."

Whether it's trendy or timeless, it needs to resonate, as a host of classes did for one ardent participant, Linda Amici. Three and a half years ago, she became, she admits, addicted to dance. The 43-year-old mother of six took classes-weekends, evenings, summer days-whenever her job as a fifth-grade teacher in Westerville would allow.

"Patrice Doran and Michael Nicholson were amazing. I found myself thinking, 'I can do that.' And I did-I was not as uncoordinated as I thought," says Amici. Before long, she also had discovered Conn, Zumba instructor Kristi Simpson and hip-hop guru Josh Romero.

Amici linked up with a nutritionist, restructured her diet and continued to dance. Recently, she became an instructor. Her first assignment was hard: subbing for Nicholson.

"You could see people's disappointment the minute I walked in. But, hey, you've got your sneakers on. You're here. Wouldn't you rather dance than not? Most everybody stayed."

Best bonus of all? Amici's dropped more than a little weight. "I look over at my 7-year-old daughter, who weighs 60 pounds. I think to myself, I've lost the equivalent of you."

Rhonda Koulermos is a freelance writer.