In a small gym off a winding suburban road one recent morning, a dozen self-described soccer moms and 40-somethings clad in stretchy workout wear waited eagerly for the command "Move your boombsey!"

They all but cheered when a tiny, muscle-hewn woman swept through a side glass door. "There she is!" one shouted.

Soon, Kukuwa Nuamah was shouting back in husky-voiced, West African-accented commands over blasting music &

smiling while demanding the women shimmy and twirl and, most crucially, move their boombseys. They happily obliged, breathlessly shaking their backsides.

"We come here and have our Beyonce moments," Tressa Bennett, 40, said while defogging her glasses after class.

The women were doing dances that have perpetually swirled through Nuamah's head while growing up in Ghana, while translating documents at the World Bank. Today, those moves have evolved into a high-octane African-Latin-Caribbean workout offered to the masses via DVD and public access television and in classes at offices and gyms on three continents &

North America, Europe and Asia &

where instructors preach the trademarked doctrine of Kukuwa: "Move your boombsey!"

The workout has turned Nuamah into a one-name wonder on the Washington region's fitness circuit. At 49, Nuamah feels on the brink of becoming fitness's next star.

"I'm like a plane on a runway," Nuamah said. "And I've just been given permission to take off."

The finicky fitness world, of course, is ever-ripe for new trends; witness the rise of Billy Blanks' Tae Bo, the current craze for Latin-inspired Zumba and the quick fall of pole-dancing classes. Nuamah said people want something new and pointed out that there is little in the way of African-inspired workouts. Experts say dance-style workouts are hot, though not exactly in short supply.

"That's the American dream &

to be able to do what you love, what you're passionate about, and to hopefully make some money from it," said Tom Perkins, president of the New Hampshire-based company Fitness Industry Solutions. But Perkins, who had not heard of Nuamah, warned, "From the business side, there's a lot of stuff out there."

More than 100 people have passed the Kukuwa instructor certification course and teach hundreds of classes a week in the Washington region, and in Japan and Spain. Two cruise lines offer packages for Kukuwa followers, who burn off pina colada calories in free classes with Nuamah. On her Web site, Nuamah sells workout gear printed with African symbols. At least 10,000 copies of her DVDs have been sold on Amazon.com and other sites, she said.

Her office is the basement of her suburban townhouse, which is for sale. Nuamah and her husband have decided to sell and pour more money into the business, which so far has not turned a profit.

"People say it takes 10 years," said Nuamah, her hair cropped short and her lips painted pink.

That is how long ago Nuamah quit her day job to focus on her workout. But the seed was planted decades before.

One of seven children born to a minister and a baker, Nuamah never studied dance; no one did in Ghana, she said. She simply copied traditional dances and made up her own, earning several dance competition titles.

"It was pure talent," she said. "When you're good, you're good."

Ghana's ethnic languages also came easily and intuitively, she said. As a child, Nuamah spent weekends at her French teacher's house, becoming fluent in that tongue.

At 16, she left for work in the Ivory Coast, then for university studies in Paris. In 1980, she followed a boyfriend to the Washington area. Soon she was working as a French-English translator at the World Bank, where she started giving "funk" dance classes to colleagues. She married a Ghanaian engineer and moved to New Jersey, then New York, and kept teaching at community centers and in her basement, where she would pack in 80 people. She called it "Le Physique."

"They loved it. People were losing weight and staying in shape &

men, women and children," Nuamah said.

"One fine day" 10 years ago, she recalled, she was back in Washington, working an administrative job at George Washington University, when her boss told her she should quit. He knew she wanted only to dance.

She quit and hit the area's gyms. She lined up gigs to teach her workout &

to which she added African moves, and then Latin and Caribbean &

more than 40 times a week.

Five years later, she wrote a manual for her workout so she could hire instructors. A business adviser told her she should pick a "catchy" African name for the class.

"Then, ding!" Nuamah said. "A light went off in my mind: Kukuwa!"

Nuamah also wanted a slogan that would make people shake their rears. Being a linguist &

she says she speaks about seven languages in addition to French &

she scoured the globe's tongues for a "cuter" reference to that part of the anatomy. She found it in the Caribbean: boombsey.

"I like that, rather than 'Move your buttocks,' " Nuamah said. "Boombsey is pretty. It's professional."

Nuamah's students say they are believers.

"Not growing up shaking like that, it took a while to get used to," retiree Phyllis Wolfe, 54, said after the Great Falls class. "But it's wonderful for the middle. Plus, there's her personality."

Nuamah still teaches about three classes a day.

"None of my instructors can keep up with me, and I'm almost 50," Nuamah said, shrugging. " 2008, you'll see me on 'Oprah.' I know you will. You know how Ellen DeGeneres loves to dance? I've GOT to have her move her boombsey."