1. Walking out the door is often the toughest part of a run.
2. Don’t compare yourself to other runners. All runners are equal: some are just faster than others.
3. If it was easy, everybody would be a runner.
4. There are no shortcuts to running excellence.
5. Keep in mind that the harder you work during training, the luckier you’ll get during races.
6. Don’t make running your life. Make it part of your life.
7. The best runs sometimes come on days you didn’t feel like running.
8. Distance running is like cod liver oil: first it makes you feel awful, then it makes you feel better.
9. Without goals, training has no purpose.
10. Make progress in your training, but progress at your own rate.
11. Runners who never fail at anything are runners who never try anything great.
12. Never apologize for doing the best you can.
13. Preventing injuries is easier than curing them.
14. Running is simple. Don’t make it complicated.
15. Running is always enjoyable. Sometimes, however, the joy doesn’t come until the end of the run.

I selected the rules that most applied to me from this list; you can generate your own list.