Adjusting Expectations to Reality
I learned a valuable lesson regarding running this weekend. Performance expectations need to be adjusted based on the weather conditions.
Over the last several weeks of training I have been timing some of my longer runs. I wanted to get an idea of what goal pace I should set for the Marine Corps Half Marathon on May 17, 2009. Two weeks ago I ran a fifteen miler and logged an 8:08 pace. It was not an easy run, nor was it very hard.
This past weekend I planned on running a half marathon and using that as my worst case pace for the race. My intention was to mimic the race day experience. I was to wake-up at 5AM, have breakfast, and start running at 7AM. My goal was to run a 7:45 pace. I was up at 4:30AM only to fall back asleep for another two hours. By the time I finished breakfast and digested my food, it was about 10:15AM.
I loaded up my fuel belt with gatorade and started running. The first 4.5 miles of my run I maintained a 7:42 pace but it seemed I was working harder than usual to do it. By the time the second 4.5 miles was done my pace had slipped to 7:48. And I was laboring, big-time to keep it going. Around the 10 mile mark, I bonked. My pace was at 8:00.
This was the first time I experienced the wall to this degree. Instead of being a hero and pushing through the last 3.1 miles, I took a left hand turn and walked home. I was frustrated. I felt strong when I started and was running some excellent times. What happened?
It turns out it was simply the weather. Most of my previous timed runs were in close to ideal running conditions with temperatures in the 45 to 60 degree range. When I ran on Saturday it was in the high 70’s when I started and climbing quickly. I realized I was hot and sweating more but figured I only needed to drink a little more gatorade. After a bit of research I found the following at Jeff Galloway’s training tips.
The hot and sticky days of summer are here. Make sure that you are making some adjustments in your running. Most runners begin to slow down at 55 degrees and start suffering at 65 degrees. Of course, the body can adapt to heat stress and push the threshold up a bit, but you usually can’t run as fast on a 75 degee day as on a 45 degree one. High humidity is also a major problem. It’s like a wet blanket; it doesn’t allow much evaporation or perspiration and your body heat builds up.
If you try to run too hard in hot or humid conditions you’ll hit “the wall” sooner than expected. Trying to maintain a goal pace in heat is like going out too fast early in the race. Temperatures generally increase hour by hour; therefore you must adjust your pace for the temperature expected at the end of the race.
Adjusting Race Pace for Heat: Estimated temperature at finish – Slower than goal pace – 8 min mile becomes…
55-60 degrees – 1% – 8:05
60-65 degrees – 3% – 8:15
65-70 degrees – 5% – 8:25
70-75 degrees – 7% – 8:35
75-80 degrees – 12% – 8:58
80-85 degrees – 20% – 9:35
Above 85 degrees – Forget it… run for fun
* Note: This chart is based upon my own experience in the heat and talking to other runners. It has no scientific verification.
No wonder I hit the wall so hard. Boink! I’ll try again this Saturday and make sure I start at 7:00AM. Race day is less than 3 weeks away!