This is a beginners class my friend, so anyone can go and jump into it.
My five year old daughter did it with me , she is now seven and still does it with me on occassion. OLd lady's do this class. its A BEGINNERS CLASS.
there is no need to build up to doing this class. just a matter of breaking thru your own ego , and no allowing yourself to talk yourself out of it.
I just finished a class a few hours ago and it was a good torture session. 90 minutes of pure hell, but hey i evicted parts of me that i didnt need, and yes that can be very uncomfortable, but at the same time, it can be very empowering.

my two cents

Bubble man

ps, hey oaxaaspice, i dont go to class, i do it at home, you can download bikrams cd off www.isohunt.com and buy his book which shows all the postures, you can also find the postures online at many of the bikrams yoga sites.
just a matter of being a little more focused, and you can do this at home just like I do.