Better days ahead?

Got on the treadmill today feeling great after two days off, and I had every intention of running using the 5K button... But, things didn't go so well! I couldn't get into a rhythm, and my legs got tired really quickly. I don't think I stayed on for more than 15 minutes. :-( I got a phone call at about that time, and I was glad for the excuse to be done with it.  I'm not sure what my problem was, but I'm sure I'll have a better run tomorrow. At least I tried...