For those of you not familiar with J.D.'s work, he is a former Marine, filmmaker and war correspondent covering Iraq and Afghanistan. For the book, he teamed up with professional fitness athlete, Nita Marquez, who is an expert in mental conditioning, fitness and choreography. She certainly looks the part of a professional fitness athlete.Anyway, the book is obviously about fitness and how to follow a system of training and diet that will put you on the path to being, if not ripped, at least looking good in a bathing suit. But the main point I gained from the book was that if your current system of diet and exercise is not getting you where you want to go, you have to change it, and that change is hard. The book has some good tips for overcoming these mental obstacles as well as detailed information for mapping out a system of diet and exercise that is right for you and that works. It's a great motivator if you are trying to get back in shape. So, though I doubt I will ever need to be fit for combat (though you never know), I would still like to be fit enough to get through life. I think this book can help.
Update: Jules Crittenden has more on the book as part of his "live forever" series.