It is informational, nothing more. There are some good points to the book but it is not realistic. I have run 5 marathons and the only way to get to the 4 hour and under mark is to do alot more training than what is listed in the book... period. If you are a mere mortal like myself (ie; you have a life, kids, job etc.) then you are kidding yourself if you think you can do this. I am not saying it is impossible, some people are in fact natural born runners. For those people they could read the wall street journal or daily news and run a 4 hour marathon on that training. Of course, speed work is important, tempo runs and long runs (no duh) but alot more of all of the above will get you to that goal (think 50 miles a week or so). I keep it around and thumb through it to look at goal times and get some pointers, thats all.