I like running and I like running in the early morning. I really liked running this winter and saw my times improve. All of a sudden, though, I slowed up. It's one thing to do that with intention. But, I didn't decide to slow down -- I just did. Up to May or early June, I could count on regularly getting in a daily 4-6 mile run that was between 07:20 and 07:40 minutes per mile; sometimes 07:10-07:15 if I felt extra good. Now, 07:40 mpm is a good run with 07:45-07:59 being the norm.
My first thought was that it was just age suddenly catching up with me. I really didn't get serious about running until 3 years ago. I was 49 and needed to lose weight and get in decent physical shape -- too much family medical history to risk any other state of being. So, now I'm 52. But I don't think age-related slowness comes on suddenly. That just doesn't make sense.
My definitely non-professional opinion is that it must be the humidity. For the last several weeks, early morning temps have been 62-75. That's not too bad (I prefer about 50). However, the humidity in Short Pump has been 90-96%. Five minutes after finishing any run, there is not a single dry spot on my body or clothes. That pretty well correlates with my slower times.
So, I endure this for a season and look forward to Fall and speedier times. Now, if that doesn't happen, it's back to the drawing board.