When the mercury rises, you can read up on my hot weather running advice to keep you going at your best under the sun. Although it takes a good effort to run successfully in cold weather, it takes a serious effort to run successfully in hot weather (more on that in a bit). Sometimes, it’s not even a matter of success but a matter of safety. Mind the fact that race organizers beef up emergency services due to hot conditions more than in cold conditions. More runners are pulled from races due to injuries caused by the heat. I’ve seen some races completely shut down because of overbearing heat and humidity. Serious injuries, such as heat exhaustion, heat stroke, hyponatremia, and death can occur if one does not take the necessary precautions. This section will show you how to combat the heat to maximize your performance and safety out there.
I’d like to start you off, however, with a bit of base knowledge that will help you grasp the gravity of the situation of running in the heat. I call it the Rule of 55. The optimal temperature for running is 55 degrees F or even a little under that. The body likes this temperature because with the help of the cold outside temperature it can keep core temperature low enough so as to minimize fluid depletion and lactic acid build up.
The adverse affects of hot weather running occur at a rather low threshold. When the temperature starts to rise above 55 degrees F, you’re already starting to run at less than optimal levels. This is because the body can no longer cool core temperature faster than it is building up. It is not noticeable in the beginning, but after about 30 minutes of running in temperatures above 55 degrees F, the body will start taking extra measures to cool itself down at the expense of your performance. You’ll start perspiring more in order to release heat via evaporation of your sweat, leading to fluid and electrolyte depletion (dehydration). Also, blood will start flooding the skin capillaries in order to get as far away from your heated core as possible (also aids perspiration process), but this action deprives your working muscles of much needed oxygen and nutrients. With less blood flow to your working muscles, the body cannot flush out lactic acid efficiently, which leads to a third adverse condition, build up that causes you to run more sluggish.
Always keep the 55 degree F threshold in mind. Rejoice when the temperature dips to that level. When the temperature starts to rise above 55 degrees F, you must take extra measures to maximize your performance, or just to keep safe for that matter. The further the temperature rises above the threshold, the more preparations and precautions must be taken, and the more regimented they must become. To grasp the gravity of the situation, keep in mind that during the summer months, temperatures range between 90 to 100 degrees F. This is nearly a 50 degree deviance from the optimal running temperature! Some places get hotter.
So, now that you have an idea of how your body works physiologically in hot weather running, you can better understand, appreciate, and apply the advice I’m about to give you. You will be more adept and safer on your hot weather runs. Use the links below to start learning some essential techniques for running in the heat.