I had a 6 mile & 4 mile tempo on the schedule with about 5:00 rest set at somewhere between half and full marathon pace. Conditions were about 76 F air/75 dew point when I started, and those creeped up to 80/77 by the time I finished. Out the door a little before 6. After a full warm up I got under way. It felt really cool out compared to what I've been used to, but I felt awfully sluggish to start out. But I surprised myself with a 5:42 opening mile. I felt great. I let myself gradually slow as the humidity did its thing, but still ran the 2nd mile in 5:56. I still felt great.
By 4 miles my shoes were full of sweat and felt like bricks. The pace slowed to 6:08, 6:13, 6:13, before I really tanked to a 6:27 final mile. 36:44ish total for 6:07 avg. I felt pretty bad by the time I was done, even though I didn't feel too hot. I just chalked it up to heavy shoes.
After about 6 minutes I got underway for the next 4. 6:19 first mile. Second mile went downhill very quickly and I felt like I was crawling. Reached 2 in 12:50, so 6:31 2nd mile. I opted to stop and reevaluate. Doused myself with water and took a drink, and I continued to feel pretty bad. It occurred to me I was showing heat exhaustion symptoms and I decided to play it safe and jog home. I managed 8:30 miles for the 3 miles back and all but collapsed upon reaching the house. I took my temperature at 102 when I got in.
So a pretty frustrating run. I take heart that the opening miles felt easy, and I was sure I could manage 6:00 pace the rest of the way. It's interesting that I really didn't feel overheated, but my temperature was probably higher than 102 after 8 miles given that I doused myself and jogged slowly home afterwards.
Is it fall yet?