Here's a dumb trick that's helped me run: I set up a custom playlist on my .mp3 player which goes for exactly as long as I intend to run that day. Then I run un

Here's a dumb trick that's helped me run: I set up a custom playlist on my .mp3 player which goes for exactly as long as I intend to run that day. Then I run until the music stops. It's trivial, but it's made a real difference.