DENVER – The walls shake as bass booms from large speakers on a front stage where lead dancers shout out commands for hip-gyrating movements.

Multicolored lights reflected off a disco ball and smoke from fog machines create surreal patterns on silhouetted bodies that sway, bounce and clap to DJ-mixed electro beats. Yellow glow necklaces, wrist bands and tennis-shoe laces that light up when feet stomp the floor break the near-dark of the auditorium.

Crowds that line the dance floor might start to think they’ve stumbled upon an acid-house party. But then they start to notice important details:

Sweat-drenched dancers here are decked in body-hugging layered tanks, yoga pants, and leggings instead of UFO pants, fuzzy legwarmers, go-go boots and glow-in-the-dark body glitter. People wait in line for a protein bar, bottled water or a fruit smoothie, not a shot, some X or a hit from a cigarette.

This isn’t a rave. It’s fitness clubbing, a new concept created by DJ Darina Miteva that blends European nightclubbing with high-energy cardio workouts.

“My goal is to bring a healthy, energizing alternative to Denver night life,” says Miteva, a 36-year-old dancer from Bulgaria who has lived in Denver for 15 years. “There is a segment of people who love dancing and socializing in clubs, but they are sick and tired of the drugs, the alcohol and the violence associated with it.”

About 30 workout fanatics attended an event launch Oct. 22 at the Sherman Street Event Center in downtown Denver where local instructors led 90-minute zumba and turbo kickboxing sessions. Emcee Palmyra Malinauskiene handed out goodie bags that included a water bottle, T-shirt and reduced club membership passes.

Miteva chose to start with the common cardio dance styles and salsa beats to ease newcomers into her concept. Between music breaks, Stephan Griffin pounded out samba beats on his Brazilian drum. In the future, each month will feature a new dance variety designed to add pace, energy and danceable beats to traditional Bulgarian folk styles, including ruchenitsa and kuchek.

Fit clubbing is a new alternative for health-conscious people to transition from an outdoor spring/summer workouts to indoor fall/winter training sessions. Lisa Rosen, 36, said the “spectacle” environment will keep the moves interesting.

“The combination of the music, the stage lights and dancers creates a different energy for a group workout,” said Rosen, who came later in the evening for the kickboxing session. “It’s easy to lose motivation or interest when you do the same workout all the time, but this atmosphere keeps me on my toes.”

Michelle Penny, 39, said she felt like she was giving a nonstop performance with continuous heart-pumping rhythms and sound.

“It’s a cool energy and so much better to be out exercising rather than lying on my couch at home on a Saturday night,” Penny said.

Davida Wright Galvin, a local instructor who specializes in Zumba choreography, says people who might avoid traditional gym settings will appreciate fitness clubbing’s party scene. Galvin regulary hosts zumba at some area clubs in the early evening downtime before crowds overwhelm the space.

“We used to party at the nightclub, but now we can party at the gym,” Galvin said.

Matt D’Amico, owner of Bodylab Fitness, just south of downtown Denver, treats his members to post-workout happy hours to foster community. And while Miteva prefers to keep her events alcohol-free, both agree that creating a social culture makes a routine more sustainable, while good music helps retain clients.

“You can’t get people in the frame of mind to push themselves harder than they ever have before by playing classic rock,” D’Amico said. “Intense, repetitive music with tribal elements gets people into almost a europhic state where they forget the pain of the workout for a half-hour.”