A Tale of Two Workouts

Yesterday I did the lower body workout. And while I felt well-trained at the end of it, there were only a few instances where I felt overly trained. I left the gym feeling more refreshed than tired.
Today I did the upper body workout. Usually I find this to be the easiest of the three strength-training days. However, today I felt weak the whole time. It could be because I haven't had a rest day this week, or because I was working out on an empty stomach; either way I didn't have the same energy level as usual. I did my exercises with the same amount of weight as usual. I figured if I became too fatigued, I could take the weight down.
To my surprise, I never did. While I felt I was struggling more than usual, I was still keeping the good form and rhythm, and managed to get through everything.

This time I left the gym tired, but good tired.