The book automatically opened to an exercise on muscle release called the Dissolved Body. I remember something like this from when I religiously went to yoga. I went through the process and then fell asleep. It was a perfectly relaxing sleep (with the exception of my son creeping into our room and crawling into his sleeping bag-- he's been having some issues lately with being afraid at night). I plan on trying this again tonight, but thought it might be particularly nice for runners. Forgive me for copyright infringement (I'm an English teacher. I know better!)... but hopefully you'll love this so much you'll go purchase a copy. :)
1. Lie comfortably in a warm room with your eyes closed. Allow your body and mind to slow down for a minute or two, by remaining still and quiet.
2. Keeping your eyes closed, take your attention to the toes of one foot. Clench the toes tightly for about five seconds and then relax them. Do this two more times. As you clench and relax in this way, imagine your toes turning to liquid, which gently flows around you. Now clench and relax the other foot, turning that to fluid in the same way.
3. Continue to work up your body, tensing and releasing. Do your shins, then your thighs, buttocks, stomach, chest, back, hands, forearms, upper arms, shoulders, neck, jaw, cheeks, eyes, and brow.
4. Your whole body should now be free to flow. You visualize this while keeping your attention on the center of your forehead.
5. Now try to tense and relax the movement in your mind: let your thoughts float to the surface and watch them dissolve and flow away.