This really should be called a pamphlet rather than a book. Although it contains some good information, it is much too brief and general to justify the price tag.
I will contrast this pamphlet with "The Purposeful Primitive", a real book I purchased at the same time. For a few dollars more, that book is very thorough, well written and contains very specific information that can implemented immediately.
I got BURNED when I bought "Underground Secrets to Running Faster". In hindsight, the term "underground" should have been a tip-off that it was shaky.