This book is for people who want to improve and achieve mastery in their chosen field. As a self-help book, it's a fairly general book that applies to wide variety of people. The most interesting part of the book is the discussion of "hot cognition" versus "cold cognition." I found this discussion interesting, and I would have like to have read more about this specific topic in more detail.

Most of the second half of the book is about what the author refers to as four fundamental practices for peak performance. Unfortunately, these practices turned out to be extremely basic: eat well, get enough sleep, exercise, and practice meditation. If someone needs to make serious changes in his/her life, this book might be helpful by putting the advice on paper and all in one place. I could be wrong, but I would guess that most people picking up this book, wanting to really improve themselves, will have already embraced these practices.

Overall, this was a pretty good book. It would probably be best for young people or those with no experience with meditation and/or healthy habits.