I've been working with this book. I had major abdominal surgery a couple years ago and if I don't stay on top of the abs exercise I lose tone really quicky and my posture & strength really suffer!
And just checked this one out of the library. I'm trying to alternate days with the books, but with travelling and sitting in airport, I'll admit I got behind!!
I like both these books because the weight routines can all be done at home and every couple weeks he changes them so you don't get too bored!