The Washington, DC Metro area has been hot and humid for the last several weeks. My running group does track work outs on Mondays and Wednesdays at 6:30 pm and the weather has been consistently in the 90s for a while. On a couple of days the heat index was in the low 100s. On Sundays, it has been in the mid- to high-80s by 9:30 am. On these hot days I've been watching my pace creep up. While I'd like to go faster, I instinctively know that I have to slow down. Actually it's my body that knows it...my brain keeps saying "is this the best you've got?" LOL
My running coach, Becca Lipscomb, and I were talking on Monday about heat and pace. She explained how the body diverts blood to cool itself, which means that there isn't as much blood available for your muscles. As a result you don't have the energy to run fast (fast being relative for the individual). She said it's much more important for me to just run, keep your heart rate down, and not worry about pace.
I went out this morning on what was a "cooler" day (it was 77 degrees when I started). I end and 85 degrees when I finished). I ended up with a faster pace than I've had on recent hots days, but by no means did I set any speed records. :) After I got back, I was reading various online articles as I ate breakfast. I came across a post by P. Mark Taylor of Wise Running called "Effects of Heat & Humidity on Running Pace". It couldn't have been timelier. It has clear explanations of how heat and humidity affect a runner.
Bottom line is I'm always going to be hotter than other runners because my clothing requirements are more stringent than for other people. During hot weather, most people are out in short sleeves or sleeveless shirts and shorts, while I have to wear long sleeves, capris, a below-the-knee skirt, and head scarf for my runs. The head scarf alone traps heat and makes me hotter (I really have to remember to wear a visor). On top of this I'm a very salty sweater, so I have to take salt tablets before my run and drink water with electrolyte powder or HEED, when most people can get away with no water or just plain water for short runs. That's not going to change so I don't bother worrying about it.
So, the hot summer weather shouldn't keep you from being a runnerd. Just be smart and slow down. Oh, and find some shade, even if it means a hillier route. Trust me on this! :)