I live in Texas, so when I say running in the heat, I really mean running when it is so hot just going from your car to your house makes you sweat. Actually this year it has not been that hot, yet. Last year, by this time, we already had 30 days of 100 degree plus.
So, if you’re like me and always training for the next race, how are you supposed to run in that kind of heat? Well the simple answer is “you just go running”.
As you run more in the heat, your body will adapt to it. The human body is an amazing machine. Even though most of us enjoy running and do it for fun, your brain is in flight or fight mode. It is doing everything it can to keep your body alive. At first it does this by keeping blood flowing to your legs and muscles so you can out run whatever you are running from to stay alive. Your heart rate increases and you start to sweat to cool your core temperature. As your core temperature increases from running in the heat your brain is faced with a choice. Keep your vital organs working and live, or keep your muscles working and run. This is an easy decision for your brain so it reduces the blood flow to your extremities and focuses on cooling and keeping the vital organs alive. If you have ever started to feel numb or tingling in your toes or fingers, know you know why. Your core temperature is getting to hot. But like I said, your body is an amazing machine. As you continue to run your brain says, “I need more blood to keep the muscles working and the vital organs alive”, so over time, your body produces more blood. With your increased blood volume, your heart will not have to work as hard to stay alive so your heart rate is reduced. You can see that all that hard training in the heat will pay off at your next race when the temperature is a perfect 55 degrees Fahrenheit.
Ok, so now you know why you should love to run in the heat, how do you adapt your body to it without getting heat stroke?
Just like every other run or race you need to plan. Temperature is part of that plan. Reduce your running intensity when training or racing in the heat. Consume extra fluids and electrolytes to prevent dehydration.
Reduce your running intensity by using this easy formula. Optimal running temperature is 55 degrees Fahrenheit. If you go up or down 20 degrees Fahrenheit you should expect a degradation of 7%. So at 75 degrees Fahrenheit if you go for an easy run and normally your easy run pace is 8:00 minute/mile. Then you should adjust your pace time to about 8:33 minute/mile. If the temperature goes up to 95 degrees (which is actually a cool day in Texas), then you should expect a degradation of 14%, so now from our example our pace would be 9:06 minute/mile.
The best way to prevent dehydration during a run is to make sure you’re not dehydrated before the run starts. The easiest way to check if you’re dehydrated is checking the color of your urine. If it is clear you’re drinking too much, light yellow color or like the color of hay – your good, Dark yellow or like ice tea color – your dehydrated. Everyone is different, so saying drink 8 oz for every 20 minutes of running does not work. If you’re thirsty, then you should drink. Make sure you’re not only drinking water. Excess water in the body can cause hyponatremia (low blood sodium). So make sure if you sweat a lot you replace lost electrolytes with a sports drink or other form of electrolyte replacement and that you are not only drinking water.
Now go out and run in the heat. You will be glad you did at your next race!