Shimon Braun is a former Israeli national gymnastics champion and a professional dancer and choreographer who performed on Broadway. He founded his own jazz dance company, called Waves, in Santa Fe, N.M., and brought it to Philadelphia when he taught dance at the University of the Arts.

He moves with the lithe grace of a man half his age. He keeps his wits sharp by creating choreography that blends classic jazz, Latin rhythms, and hip-hop.

For the last three years, he has offered a dance workshop at Main Line Health & Fitness in Bryn Mawr, and his current students are a group of 10 women, all mothers, ages 35 to 63. But you would never guess it by the way they move - swiveling their hips, rolling their heads, strutting like vamps, prowling like cats, executing high kicks and sharp pivots, tap-dancing and toe-stepping, moving in synchrony to infectious, thumping jungle beats.

All of them seem to revere and adore Braun, who returns the sentiment.

"I love them," he said. "As a group, they're so dedicated. All my life, I've worked with professional dancers. . . . These ladies are not making a living at it. They just enjoy doing it."

At the start, the workshop was designed to provide advanced training for women so smitten by dance that they wanted more than they could get at Braun's Saturday dance classes. The workshop, held for two hours on Sundays, gives the performers a chance to perfect their skills as a group to Braun's original choreography.

Braun has been so taken by the women's progress that a while back he decided to celebrate their achievement with "a little show." Generally, the women practice for four months, then perform the dance. Next Sunday, at 4 p.m., they will showcase their latest dance at the Performance Garage, 1515 Brandywine Street in Philadelphia.

On a recent Sunday, I watched them rehearse and I can promise that all who come will be well entertained. Their proficiency is especially remarkable in light of how little time they have to practice (only two hours a week) and how busy they are in their "real lives." Also abundantly obvious is how much joy they exude in mastering the moves.

After the rehearsal, I talked to some of them. They are a diverse lot, united in their passion for dance and affection for each other. Dancing is a way to express themselves, they said, and ease stress. "I call it my therapy," says Janet Rosen, 57, of Wynnewood. "After a rough week, I go to dance class, and everything else leaves my mind."

Debbie Fox, 53, of Wynnewood says: "I love the idea that no matter how old you get, you can still improve and get stronger every day and do things now that you may not have been able to do 30 years ago, just through hard work." Julie Lafferty, 47, a former member of the Sixers dance team, hopes that mastering the intricate choreography will prevent Alzheimer's, which runs in her family.

Debbie Narcise, 58, of Broomall is the group's "ringer." A dancer since she was 10, she studied and performed with the Pennsylvania Ballet for several years and is a dance instructor now. Watching her perform with such crisp fluidity, one would never guess that she suffers from rheumatoid arthritis. At times, the pain has been so bad that she couldn't even move her head.

"I give myself a needle once a week and I'm on all kinds of medications," Narcise said. "When I dance, I'm in a lot of pain but I don't think about it and I don't show it. When I'm on the dance floor, I can still move around like I'm 20. I may not feel so good, but I feel a lot better than just sitting in a chair."

Sarah Swarr, 47, an occupational therapist from Schwenksville, began dancing at age 7 with the Pennsylvania Ballet. She continued dancing with modern dance companies and at theme parks, on cruise ships, at resorts such as Atlantic City and Las Vegas, and with touring companies abroad.

Then in 2000, at age 33, she was involved in a terrible car accident. She was thrown through the windshield and was in a coma for three weeks. Her injuries included brain trauma, a shattered kneecap, a broken jaw and collarbone, and a back that had to be stabilized with a rod.

The accident meant the end of her professional dancing career but not her love of the art. "Once a dancer, always a dancer," she said. After multiple surgeries, she began practicing dance again, at first tentatively, as a form of therapy. Such was her desire that she eventually enrolled in Braun's class, even though she was convinced that following his choreography would be well-nigh impossible.

"Everybody in the class has something they're coping with and they're all very supportive," Swarr said. "I can't jump, for example. But Shimon always figures something else out and makes it so I'm able to do what I can. Everyone helps me figure out how to compensate for what my body is not able to do now, and it's so sweet and comforting. It gives me the opportunity to keep it going. It's an amazing thing for me."