Purging the poison

Was it the beer and pizza on Monday that robbed my legs of energy on Wednesday? Shouldn't have, but that's the only thing I can think of after Wednesday's short tempo run checked in as a fairly high-effort affair.
The weather was very nice, and the ankle I twisted Monday night was 80 percent recovered, so I did my run outdoors. The schedule called for 3 miles, but after the excesses of Monday - and subsequent overeating Tuesday and Wednesday, I wanted to burn a few more calories. I went 5.5 miles.
My overall pace was fine, but nothing too fast. The average was 8:42, and at that pace I should have been comfortable all the way. As it was, it took me at least three miles to fall into an easy rhythm. I noticed I was breathing heavier than normal most of the run. It was only in the last mile and a half or so that I got that under control. None of it was excessively bad. It just wasn't what I would normally expect at this point. Today could be completely different.