I have started doing it daily in the last month. I was doing it a couple of times a week. I started daily because I have been running and yoga really helps stretch out my muscles. I pulled something in my thigh/groin area a few weeks ago and the yoga has really helped stregthen my legs in areas I thought were strong. Plus, the core training is really helping that. Again, I thought I could get away with just running. I realize I need to add more to my routine. Yoga is incredible. I just need to meditate and not think of all the stuff I have to do.
I have pulled some podcasts off of Apple and rotate different free ones off of YogaJournal.com, Yogamzing.com and Yogadaily. They offer free stuff since I didn't want to purchase a dvd.
I do the elliptical also. Some days it is soooo hard I want to cry. I can't figure out why. I do love running though.