What about "chicks"?
I'm not sure "chicks" is really an acceptable reason to take a yoga class. I'm all for "superpowers" however.
I think I would like a yoga-themed super. I am imagining that they would maybe go very slowly, but with amazing stretchiness. Also, there zen centeredness would maybe mellow their enemies and unlock seemingly impossible obstacles. Yoga is down with skin-tight uniforms, though, so that necessitates a superhero to represent. Their impetuous sidekick could be Tae Bo themed.