You could say it's mostly about "holding your head up high", which is an immense oversimplification of what they call the basic movement. I don't know why it improves your self-control, but it does. I downloaded this off the torrent network a couple years ago, and just bought a hard copy. This is one of those books that you have to study and is definitely not a quick fix. I didn't have money to hire a trainer. This book ranks right up there with ""Trigger point therapy manual" by Claire Davies. He was a piano tuner who began having trouble with his hands and wrists. That one is also not a quick fix.
I'm writing this because some jerk implied that this book caused tendonitis, which is ridiculous. Your going to have to accept that there are people out there who, whether it's deliberate or not, spread false information. Especially with the things that are not quick fixes.