On a quiet Sunday morning, at a dance studio in Minneapolis, 15 barefoot women are enthusiastically twisting their hips to a three-count beat. A casual observer might surmise that a wild tango class is in full swing, but not for long. Over the next hour, instructor Jill Goux will lead her blissed-out charges through sharp tae kwon do punches, stoic yoga poses, and make-up-your-own modern dance moves -- a routine that's as varied as the playlist in the background.

Light-years away from the 'go for the burn' era of aerobics, these women are practicing Nia, a mind-body discipline that has garnered a cultlike following since it was introduced in 1983. Pursuing an alternative to the hard-driving, high-impact fitness that characterized the '80s, founders Debbie Rosas and Carlos Rosas looked to nine classic disciplines for inspiration. Their creation, Nia, which stands for Neuromuscular Integrative Action, is a fusion of martial arts (tai chi, tae kwon do, and aikido), dance arts (jazz, Duncan, and modern), and healing arts (yoga, Feldenkrais, and the Alexander technique) set to music.

One central idea in Nia is that your 'body's way,' the design and function of each person's unique makeup, guides the practice. 'Connecting with physical sensation is how you begin to live a conscious life, to learn about yourself and work out in a way that's respectful to the body,' explains Debbie Rosas. Rather than indoctrinating a strict set of rules, Nia is about adapting movement to your own personal rhythm and comfort level: One person might choose to jump while another softly sways.

It is this adaptability, and accessibility, that gives Nia a democratic niche in the fitness market -- and a passionate following. Rachael Resch was disabled with severe asthma until she found Nia. 'It helped heal my lungs,' she says. Traditional exercise didn't work for Jennifer Alexander, who uses a wheelchair due to Friedreich's ataxia, a neuromuscular disorder -- but Nia does. 'I can't do the leg movements, so I adapt them with my arms,' she says. Bill Stewart was overweight and fed up with boring cardio machines when Nia entered his life and he dropped 80 pounds. 'It was the one thing I enjoyed doing,' he says.

Once Nia-phytes, Resch and Stewart are now among the more than 1,500 certified Nia instructors worldwide. The Rosases have developed routines and music choices for teachers to use, but instructors are encouraged to experiment.