1. Music / TV
2. Listening to audiobooks. There are many audiobooks that can be downloaded right to ipods.
3. Speed Intervals: Increasing the speed for certain intervals, such as a half mile or the length of a song can boost performance and break up monotony.
4. Adding Hills: Increasing the incline for a few minutes here and there is another way to challenge oneself and take the mind off of the treadmill. Remember, there is no down hill on the treadmill so after the run, do 20 lunges with each leg.