"Zumba is the best thing on the planet," said Marissa Schor, a Zumba student.
While it's not the only program to go from trend to tried and true, Zumba has staying power, now celebrating its 10th year in action.
"The music is blasting, the energy in the class is just unbelievable," Schor said.
Welcome to Zumba - 60 minutes of body rocking, hip swaying, shoulder shaking fun to all kinds of Latin tunes.
"You can dance, you can be yourself. Even if you don't know how to dance, it is such a great workout," said Melissa Zugell, a Zumba instructor.
It remains popular at fitness conventions like the International Dance Exercise Association Convention held in Los Angeles, where instructors come to stay current with fitness trends.
The program offers teacher instruction through a Zumba academy. There are various levels of certification - Zumba for kids, seniors, aqua Zumba and Zumba toning.
But the big seller is the main Zumba class. There are little vignettes within each class that offer specific moves that many of the students seem to know, but memorizing dance steps is not a requirement. While many hop around, much of the movement comes from the core or mid-section of the body.
"The more you come, the better you will get at it. The more your hips start to move, and you get into the feeling of it more," Zugell said.
It is also a form of social entertainment, where those who love to move feel at home. Those taking Zumba don't call it fitness, they call it a party.
"(It) really expands my circle of friends and I really feel that it's an awesome atmosphere," Schor said.
Kendell Hogan, Crunch Regional Group Exercise Coordinator, said they decided to have Zumba nights, with special lighting and a live drummer.
On Friday night, it's a whole different kind of happy hour at Crunch. They stir it up and shake it up.
Not every class comes complete with a drummer, but no surprise the Zumba crowd loves the extra motivation.
There are over 60,000 locations to take Zumba classes.