Instruct: Classify Amazon reviews into positive or negative sentiment
Query: might be OK if you're 20 and ripped!

Mr. Kest apparently has no concept of "beginner". His easiest program is WAY over the head of this 50ish and very athletic lady. Unless you are extremely strong and totally flexible and have been doing Yoga for years, you risk injury if you try to keep up with even the easiest of these programs. He tells you to modify the poses to be easier - and do only what you can comfortably handle and breathe thru, but virtually all of the demos are at the most difficult level. His "warm-up" is no warm up, and initially, the length of time he has the demo people hold the poses is ridiculous although the pace picks up to be TOO quick toward the end.