There was a time, only a little over a year and a half ago, when I couldn't run more than 1/8th of a mile. Today I ran 9 miles. I ran 8 two weeks ago, so I just took the speed down a tenth of a mile and decided today I would run 9. That voice in my head tried to tell me "You can run 6 today. An hour of running is a good workout. You don't NEED to run 9. That half-marathon you're working towards isn't until October..." She only said that a few times, but I won out. I just listened to my music, watched MTV (the gym got 8 cable channels back for the aerobic equipment, better than nothing!) and plugged away. I definitely do the numbers game, breaking everything up, to see how far I've gone, trying not to concentrate TOO much on how much I have LEFT to go. My favorite part, other than hitting the stop button and jumping onto the rails? Seeing people come and go on my neighboring treadmills as I go at it!