This book appears to be a pretty darn good resource for fitness prescription and testing. I have read much of it and it is pretty well written and quite clinical. So if that's what you need, then this book is it.
However, I was intending to get books to study for the ACSM Personal Trainer certification. This is NOT the book for that. Now granted, they recommend this book on their website, and it may be helpful, but the intended primary study source is the ACSM's resources for the personal trainer...book. So if that's what you are trying to do (like i was) then get that book, not this one. If you want a bunch of cool knowledge about exercise prescription, then this is the book for you.