Shannon-Elise Tietz is gyrating on a pole, her hands gripped high, body undulating up and down in sync with music blaring from big speakers beside an exercise ball.

"How ya feelin'?" she shouts, looking out to the group, shaking her booty to demonstrate a move.

It's a Wednesday evening at Wolf Studios in Minnetonka, and Tietz, 33, is leading a 45-minute session called Strip Fitness. On my knees at the front of the class, in the shadow of a stripper's pole, I raise my arms and sway, the lone male among a half-dozen wiggling women.

"You got it!" Tietz calls out, the music thumping, ringing in my ears.

Advertised as a way to "tone your booty, legs, arms and abs with style," Wolf Studios' dirty-dancing-influenced class is the latest Twin Cities entry into a new exercise form that borrows moves most often associated with strip bars and burlesque shows. Lighted platforms, poles, folding chairs, suggestive moves and thumping music mix to create a sweat-inducing, heart-rate-raising session that Tietz says can be as serious a workout as anything she offers.

"It's a ton of cardio, your heart rate going up and down through different fat-burning zones," she said.

Looking sexy, keeping fit

Popular on the West Coast since the early part of this decade and bolstered by exercise-video stars such as Carmen Electra, stripper-influenced workouts take cues from erotic dancing and add strenuous aerobic procedures. Participants hang and swing on poles, step up and down off platforms, dance to fast-paced beats and gyrate in varying degrees of suggestiveness. Some studios encourage starting with extra clothing layers, so feather boas and tank tops can be thrown off in the fit of a steamy workout -- although the stripping never goes further than sports-bra deep.

Melissa Eisler, a managing editor at the Active Network, an online publisher of sports and fitness websites in San Diego, said exercisers need to have an open mind when attending a strip-based class.

"People who are easily offended should set aside their inhibitions before walking through the door, or they probably shouldn't go," she said.

Wolf Studios founder Matt Rubenstein classified Strip Fitness as "adults-only."

"It can get quite risqué," he said.

Ali Kuhlman, 22, of Plymouth, has not told her family about her participation in the class. She said her boyfriend's jaw dropped when she mentioned the details.

"He asked when he could come watch," she said.

But like most of the pseudo-strippers at Wolf, Kuhlman signed up to burn calories, not to hone her skills on a pole. A dancer and a self-proclaimed fitness freak, Kuhlman said Strip Fitness is just as intense as her other regimens but more fun.

"The music is a huge part," she said. "It makes you want to move and shake."

At Flex Appeal, a facility touted as "Minnesota's premier striptease and pole dancing fitness studio," founder Maria Scherber has been teaching striptease dance aerobics, pole dancing, chair striptease and "body booty camp" since 2005.

The studio, on Washington Avenue S. in Minneapolis, features mirrors, gleaming hardwood floors, speakers and floor-to-ceiling poles for dancers to twirl, dangle, thrust and gyrate at will.

Another Minneapolis studio, the Firm, started its Strip Tease class in early 2007. A dozen exercisers show up twice a week to "bump and grind," "do some belly rolls" and "loosen the hip joints," according to the class description.

Doug Melroe, a manager at the Firm, said some gymgoers initially joked about high heels and racy tops. But once they saw the class in action, he said, even fitness fanatics realized that it was a true workout. Men make up about half of most classes, he said.

It's time to hit the pole

My time on the dance platform at Wolf was decidedly unsexy. Attempting to watch Tietz and copy her moves, I noticed Kuhlman and other women giggling.

For a few minutes, I pawed and wiggled in my gym shorts, on my knees, participating in some kind of come-hither routine I didn't understand. Then we stood up to dance. I rocked my hips. The music pumped and screamed, blaring "See you jigglin', see you dance."

Tietz was rocking out, her hair a flying frenzy over a tight, toned body. I took to the sidelines once she brought out folding chairs to straddle, the women in a trance still as the simulated striptease stomped on.

Tietz leaped to grab a pole, swinging and hanging with no hands in demonstration. Her body was still, legs crossed and bearing weight on a thin metal pole, tendons in her neck popping to accentuate the effort.

Sexy? Strange? Silly? Maybe. Strenuous, too.

Strip Fitness, although not a class for me, was among the more enthralling 45 minutes I've spent in a health club lately. Despite the skeptics, the class is a true workout.

Stephen Regenold is a Twin Cities writer and author of the syndicated column