I left about 1 pm for my run. I wanted to run earlier in the day to catch the mid-day warmth. The temperature when I left was 40 (F) and 38 when I returned. It was a nice day for running, a reasonable temperature, no wind, and lots of sun.
I felt pretty good when I started running, doing 1 minute 50 seconds running and 40 seconds walking. However, I had only gone half a mile when I detected feelings of tiredness, and I said to myself, "I'll only be able to do one mile if I don't slow down." During that half-mile, I ran faster than I've been running, although I didn't push myself to run faster. I did slow down, and I felt better. I had hoped to run for 140 minutes (my long run), but after I had gone 2.6 miles, I recognized I was tired, and I turned around and headed back. On the way back, I jogged less and walked more to give my body more rest. I also took one brief rest stop on the way back. I turned around, because my body told me to do so, and I didn't want to mess up my Monday run by being overly tired. In my 100 minutes of running, I completed 5.2 miles.