I wasn't sure what to name this post, but "Friggin' Heat" seemed to encapsulate it. I was thinking about "I Hate Heat" or "Hitting the Heat Wall" or "I'm Never Going to Make It".
Sooooooo... what happened? My run today was supposed to be an 8 miler, with 6 miles in the middle at a 7:37/mile tempo pace. I figured I'd aim for a 7:30/mile pace. I didn't get out the door as early as I would have liked, so by the time I was on the run, it was 9:30 am and the sun was shining... brightly... warmly. It was about 85 degrees F (just shy of 30 degrees C.) by the time I started.
I couldn't keep my pace down according to my instant pace on my GPS, but after 1 mile I was at 7:45. A bit fast for my warmup run, but so far so good. I picked up the pace a bit and did the next mile in 7:25 -- exactly where I wanted to be. The next mile at 7:33 -- okay, starting to slip a bit. I had to pick up the pace just a bit -- but the GPS never seemed to have have me where I felt I should be. Despite this, I ended up at 7:19 for the fourth mile (4:35/k pace).
By now, I'm getting hot. Really hot. And I'm not sure how I'm going to handle things -- especially since I know I was pushing my heat envelope, as it were. So I pulled the plug -- there was no way I was going to keep that pace for another 4 miles and, in fact, I wasn't sure if I was going to make it home. So my strategy was to just keep running at a sufficient pace to get back to our office (about 500 m closer than home).
Surprisingly, my pace -- while slow -- was still acceptable. My next two miles were at a 7:40/mile and 7:51/mile pace. I felt like I was crawling -- but in fact, I was running faster than my target marathon pace of 7:55!
So, I did 6 miles of my 8 mile run. But my average pace was 7:37 overall -- right on what I was supposed to do for my tempo run. But more importantly, I learned a couple of things: Don't try tempo runs in the heat -- it ain't going to work. And, that now my 'crawl' speed is still faster than my target marathon pace.
Hopefully I won't need either of these pieces of information come marathon day!