Female Speaker: Shimmies, shakes, and figure eight. Belly dance moves that have nearly two dozen dancers working up a sweat during this class at New York Sports Club in Manhattan.

Francesca Gambelli: We have women in their 60s, 50s, 40s, 20s, we have teens, we even have some kids doing belly dance.

Female Speaker: An ancient fertility ritual, belly dancing today is a hot workout in gyms across America. Francesca Gambelli learnt a belly dance in Morocco, and has been teaching it here for 3 years.

Francesca Gambelli: It's just a great workout and you don't realize you're really working out. You are just dancing having a great time.

Female Speaker: Hip movements down the abs and mid-section. Once you get the arms going --

Francesca Gambelli: It becomes also an incredible workout for shoulders, upper body, torso, also for legs.

Female Speaker: It's a great alternative to weight training, because I really felt my abs working, my glutes, my lower back. It was excellent.

Female Speaker: I am 55 years old. I hate machines. I don't like pain, and I really needed something to really ease me back into getting in shape.

Female Speaker: Although the class attracts mainly women, the many benefits of belly dancing or what persuaded Todd Lash to try it out?

Todd Lash: I am a dancer and I like all forms of dance, and I think that belly dancing should be able to help me isolate my center and work on my core.

Female Speaker: But the women here say belly dancing is about more than breaking a sweat, it's a fun, flirty way to celebrate their femininity.

Francesca Gambelli: A lot of leads coming and they are shy. They don't think of themselves being attractive or feel they are uncomfortable with their bodies, but after a few classes you just see them shining and you see them like -- those mental obstacles and they start feeling more comfortable with their bodies.

Female Speaker: As a woman, it's really liberating. I thought I was going to be scared and felt really self conscious, but you just kind of want to bear it all and let loose and have fun.

Female Speaker: I would highly recommend it to the young and old, because it is a lot of fun and it also helps you, as far as a woman with your self image. You really begin to feel sensual and exciting as you dance.

Female Speaker: An ancient dance in the modern world that's changing the lives of women and even a few men, a shimmy and a shake at a time.