A tip from chapter 7 of the Non-Runner's Marathon Trainer, Part 1 talks about learning to focus or concentrating on what you are doing. This is the opposite of "spacing off" the book says. Later in the book they talk about associative and dissociative mental techniques, that is something different that we will get to know more about later. But staying focused does not mean that you are so intent on what you are doing that you can not talk or enjoy the scenery along the way. What it does mean is that when you start to get fatigued the first thing that happens is you lose your form. What happens then? When your form falls apart, you begin expending more energy to go slower. You start leaning forward from the hips shortening your normal stride, you begin carrying your arms too high, fatiguing the shoulder muscles even more, you begin over rotating the upper body, spending energy going from side to side and less straight forward. Concentrating is not easy when we are tired, it takes practice. I have a T-shirt we gave out to Hilltoppers years ago that said simply, "body check - attitude check". To our team that meant that as soon as you realize you have lost your focus, check your body to make sure your form is good, then check your mind to make sure you are using positive self talk. Like physical training, mental training does not come easy, put practice it and you will have a valuable tool to help you on those long runs! Let us know if you have success with this.