So what do you know about yoga
Not much, other than it started back in pre-Vedic Indian traditions, and has to do with slow movements.  You?
My sister engages in it. I know it has postures called aasans and you say Om Shanti Shanti. Did you know that?
No.  So there are chants that go with it?
Yep its basic Hindi words. Yoga is mostly associated with Hinduism but Jainism is related to it too as well
I can't help but think of Gregorian chants.  That would be a little weird though.