Instruct: Classify an Amazon review as either positive or negative.
Query: Very effective

I bought this video, and was not sure how I would do having had a previous L4/L5 back operation. The more limber I stay, the better. This CD really helps! You can feel the burn in your abs. However; he does a set of straight leg lifts which I cannot do, but I modify and still feel that this is a very effective abs workout. Like I said, a few modifications and I'm good to go!