I felt more energy today than I have recently. I felt pretty good during the run, so I'm surprised to see my HR numbers as high as they are. 159-164 bpm for 4 miles -- a few months ago, 155 bpm seemed unsustainable. I did not feel like I was pushing super hard (except for the last mile, which was a bit of a push).
Afternoon run, temp around 80, so it was HOT! Maybe that is part of the story with HR, etc.??