On a rooftop parking lot in Coral Gables, Fla., with temperatures in the low 50s, a crowd of all ages shimmied and shook, sweated and smiled as DJ Francis played an eclectic mix of dance music.
But this wasn't just another wild South Florida party. It was a special Zumba class for charity, led in January by the creator of the global craze, Alberto "Beto" Perez.
The charismatic Colombian in cargo pants — who has become a rock star in the fitness world — climbed onto the roof of a Chevy minivan that doubled as a stage. He demonstrated salsa steps, the merengue march and many other Latin-inspired dance moves — all while also cuing the drummer and bongo player.
For an hour, 75 of his adoring fans — and even the minivan — moved to the beat.
"Everybody loves it; everybody has fun," Perez said while posing for pictures with his Zumba faithful, some having traveled from as far as Canada.
Two days later, Perez flew to New York to appear on the morning television show "Live! with Kelly."
"You must be so rich by now," host Kelly Ripa gushed to Perez, 41.
Perez's Zumba classes, with the motto "Ditch the Workout, Join the Party," were strictly a South Florida phenomenon 10 years ago.
Today, Zumba Fitness has become the world's largest branded fitness program, with about 12 million people taking Zumba classes weekly at 110,000 locations in at least 125 countries, said company spokeswoman Allison Robins.
The private company won't reveal information about its finances, but Zumba Fitness' empire appears to be flourishing. It is doing so on the strength of a growing army of certified instructors who spread the Zumba gospel to such distant outposts as Iceland, Nepal, Papua New Guinea and even Afghanistan — at the Kabul Community Center.
Zumba instructor Liz Ramirez, a U.S. Foreign Service officer with the U.S. Agency for International Development, said in an email that she teaches classes in the heavily guarded U.S. Embassy compound that was attacked in September.
"In an environment like this, Zumba has been my lifeline," Ramirez said. "It provides me with a creative outlet … a needed balance to the challenges and demands of the workplace. The music is upbeat and the environment is supportive."
And you don't have to be in a war zone to need a stress reliever.
Florida Keys attorney Dorothy Harden discovered Zumba classes a few months ago and is hooked.
"It feels like exercise because you are sweating, but it's so much fun you forget you're exercising," she said. "You get your inner-dance on. And now I can fit into my clothes from college."
Many fitness crazes have come and gone: barefoot running, hula hooping, Nordic tracks and strip aerobics, once a favorite of Carmen Electra. Staying power is tough in the ever-evolving fitness industry.
John Figarelli, founder of the National Fitness Hall of Fame Museum and author of "The History of Fitness: Fads, Gimmicks and Gadgets," said: "I think the owners of Zumba did a great job of getting it going from a business standpoint."
Zumba Fitness does not charge gyms to carry its classes. Instead, it trains instructors and gives them the license and use of the trademark if they join the Zumba Instructor Network.
"We're helping the instructors to become entrepreneurs and make a living out of it," said company co-founder Alberto Aghion, a Florida International University alum who last year entered the school's Entrepreneurship Hall of Fame.
It's a sound strategy, said Figarelli, whose book covers 100 years of working out, from 1900 to 2000.
"Most group exercise instructors will just go with the next popular class. But if Zumba is your business, instructors will stay with that."
Ensuring instructors are successful has become the company's main mission.
"We have three people who all they do is call up gyms all day and try to find instructors employment," said company co-founder Alberto Perlman.
The company has made Zumba instructors easy to find, with a worldwide listing that includes all of their network instructors' classes regularly updated on the company's website.
Instructors also receive new music and choreography about every two months. The music department now creates music just for Zumba classes, with original songs that include "Zumbalicious," "Que Te Mueve" and "Caipirinha," which was a No. 1 song in Israel.
Zumba Fitness makes its money on its instructors' academy, instructors' courses, a monthly fee for instructors in the network and on all of its branded merchandise.
The company has built its own line of hip, colorful clothing and footwear, workout DVDs, two video games, original music and a lifestyle magazine, Z-Life.
The first Zumba Fitness video game came out in 2010 and was a big success, selling more than 4 million copies — and outperforming Harry Potter's new video game. "One headline said, 'Harry Potter and magic can't vanquish Zumba,'" Perlman said.
International music stars Pitbull and Wyclef Jean have seen the value of the Zumba loyalists and their love of music. Both performed at Zumba's national convention last year in Orlando, Fla., where 7,000 instructors from around the world congregated.
This was not the business model when Zumba Fitness was founded in 2001 in Aventura, Fla., by the "three Albertos" — creator Perez and boyhood friends Perlman and Aghion, both entrepreneurs in their mid-20s and natives of Colombia.
The trio's original plan was simple: produce VHS workout tapes of Perez's popular South Florida classes to sell around the country on infomercials.
The biggest problem for Zumba these days is counterfeiting, piracy and protecting its trademark.
"We are spending seven figures on fighting this," Perlman said. "Counterfeiting is crazy. We see illegal instructors all the time."
Clark writes for the Miami Herald/McClatchy.