Why Couldn't I Do 50-minutes?

Today, I started a high intensity cardio workout that was 50-minutes long. Lots of jumps, jacks, etc. I've done it before to completion, although it was challenging. Today, I got to 22-minutes, and knew I was "done in," so went to the cool down. I was exhausted. Could it have anything to do with the heavy weight lifting day I did yesterday? It was only upper body, but it was intense and an hour long. Would that really have an effect on my energy level today?

What do you think?