This book is so unique in the sports, fitness and health fields, that it creates alternatives to them. It establishes efficiencies for movement that are exact science, so they can't be altered and give equal results. Other authors giving instruction in this area rely on their academic and/or high performance status for credibility. In spite of their credentials they have missed the essential physical laws to overcome inertia, and how to use gravity and momentum for speed. As a result they lead people to contract all their muscles at once, by having them attempt to use the wrong ones. Their student's natural-feel guides them to dominate with correct muscles in spite of what they were taught. Being confused, they still use the wrong ones too. Jack Nirenstein relies mainly on examples of his discoveries that are immediately convincing, yet never kwn before. They have surprised everyone hearing them.