Re: Hot Yoga/Bikram
My GF does it. The room is like 100*, and her class does something like 26 poses for 75 min total. She's wore out when she's done. It's a lot of isolated muscle exercise held at tension, so she's pretty sore the next day. There is another class thats 15min longer that does more and different poses, I suppose it's more advanced.
I would consider this as a nice alternate work out day. Lots of stretching, isometric exercise, muscle confusion, all that stuff, but wouldn't exclude cardio and lifting.