If it was merely a matter of being a ‘near occasion of sin’ (which was being discussed earlier in the thread) then I don’t think that it would be generally sinful - like Jimmy Akin explains, if you have a reason for doing something which may tempt to sin (eg, for exercise and relaxation) and the temptation to sin is not that great (as the OP said, he has a strong faith) then it is okay to enter into that situation. You sorta have to compare the temptation vs the rewards.
However, from what I have read here and around, yoga is not merely a temptation to sin or a near occasion of sin. It sounds objectively sinful as you are actually participating in the mystical practice just by going to the classes (apparently the postures used are evil symbols and the words you say have already been explained on this thread to be wrong).
But I’m not sure about this, don’t know much about the sources. Maybe (if you really want to do yoga) you should get a clarification about this, maybe ask about it in AAA or from some other source you trust. Until and unless you’re reasonably sure that it’s not objectively sinful, then don’t do it, because it seems likely that it actually is sinful.