I love this book because of it's pictures. It demonstrates which primary and secondary muscles are being workied during various exercises, which is pretty neat. Other than that, it isn't very useful. It doesn't provide good routines or workouts that best develop those very areas it demonstrates. Thus, it's not a good workout book, just a nice reference. It's nice to have, but not necessary. Buy it if you like pictures, but don't waste the money if you can only afford one book.