One of the New England phrases that my kids picked up during our 17 years there is "wicked good", meaning the best possible. That's how I think of my run this evening. I left home after the sun had set, and by the time I finished the 1.5 miles of the new path, it was getting dark. For 5 miles I felt strong and thought I could go on forever. I did start feeling tired during the last 2 miles, but I continued my strong running and finished without the "dragged out" feeling that I sometimes have when I get tired. The temperature was in the low 50s (F) and high 40s during the run, and that helped me to continue a strong run. When I say strong run, I'm not saying that I was pushing myself to go faster. I'm saying that I felt strong, and that feeling continued with me to the end. I let my body set the speed it wanted to go. My wakeup heart rate was 53 this morning, a bit higher than earlier in the week.
I wore one layer during the run, and my core felt fine all the time. My arms did get slightly cold toward the end of the run, no doubt due to more blood being diverted to the core as the outside temperature started to fall.
Just a comment on getting a bit tired during the last two miles. I'm not running very fast, and it took me 1 hour 45 minutes to do the 7 miles, including a few stops for picking up litter and some walking breaks. I ran for 1 1/2 hours before I started to get tired, and that's pretty good for my present condition.