Well, almost every day. Last year I took a yoga class three times a week for six months, and really liked it. The strength and flexibility benefits were slow, but definitely noticeable. And I think the time spent breathing deeply is important. However, it was just too time-consuming to go to an hour and twenty minute class three times a week. So after my six-month membership was up, I decided I would try to do yoga at home for 30 minutes or so three times a week.
Well, that was almost a year ago, and I haven't been doing a very good job of keeping it up. At most I do it once a week, and many weeks I haven't done any yoga at all.
So I've decided I will try to do 15-30 minutes of yoga every weekday. I've been doing it as soon as I get home, before I look at the mail, or read the paper, or start making dinner. I change my clothes and roll out the mat in my bedroom, and start. I am very much a creature of habit and routine, so I'm hoping that if I start doing this regularly enough, it will "take" and I'll keep it up. And the fact that it's not particularly time-consuming helps a lot. It's also a nice de-stresser at the end of a usually stressful day.
One thing I am looking for is sources of yoga poses, so I don't get into a rut of doing the same routine every day. Yoga Journal has a build-your-own-routine feature on its website, so I will be trying that, and there are also some yoga routine iphone apps which I want to check out.