This morning I went out for my short 4 mile training run feeling pretty good. I started off the run and everything felt in sync and I was going pretty fast so I pushed to keep my speed up. The result is that I crossed the 5K mark with a new personal record of 24:30, running the 5K at a pace of 7:54 per mile. At that point I was running out of steam because I had been pushing for speed so hard, so I couldn't maintain that pace and finished the 4 miles in 32:35, about 8:08 per mile overall.
It was a good run today, but the interesting thing is that, at about 2 miles, I knew I was pushing a little too hard and started to think it would be OK to run a 5K today instead of the full planned 4 miles. In the grand scheme of things, I don't think I would have been worse off had I quit at the 5K mark, but I knew that would take a psychological toll if I missed my planned mileage for the first time in my training. So, I kept running, just a little slower, and finished all 4 miles.
I'm really glad I didn't quit early and pushed through it. The important thing with a training plan is that you stick with it and I did just that today.