The concept of "junk miles" is that too many cyclists spend too much time in zone 3, in between truly hard and truly moderate or easy. This tires the cyclist while providing neither the fat-burning advantage of easier rides nor the stimulation of harder rides. Hence the admonition that too many cyclists ride neither easy enough nor hard enough. I have Mr. Chapple's book. What he is preaching is far from the concept of "junk miles."

Mr. Chapple has studied it in his coaching practice as have many other coaches. I don't know of a long-term double blind study, but that sort of study is ill-suited to the complex issues involved in season-long periodized training. My practice has been to try out various theories on myself and see what they do for me. I've learned one thing for sure, and that is that lots of base miles are a huge help after the second hard pass of the day. The more the better. However I haven't had the discipline or sufficient interest in self-denial to stick with Mr. Chapple's program. The joy of whomping on someone who usually whomps on me always gets the better of me.