Summer is a great time of year. But with summer comes running in the heat. There is no need to be afraid of running in the heat if you properly prepare.

Give your body about two weeks to heat acclimatize. As an engineer, I find this fascinating. Your body will physiologically change over time to adapt to running in higher temperatures. Your body will begin to change as it experiences recurrent exercise in heat that causes an elevation in core body and skin temperatures. It doesn’t happen overnight, but it does happen relatively quickly.

The blood vessels in your skin will vasodilate or widen to dissipate heat better. Your regular sweat rate will rise to better cool you. Your body’s typical core and skin temperature will decrease to counter the external stimulus of heat. And the concentration of electrolytes in the body will change to adapt to the higher sweat rate. This is fascinating stuff that happens automatically! You only need to be patient.

During the heat acclimation period, take it easy and give yourself a break. Your runs will be at a slower pace than usual because your heart rate will be higher than normal. You’ll be overheated because you aren’t sweating enough. You’ll cramp because your electrolyte concentrations are low, and you are likely not yet hydrating enough. Be patient with yourself and your training during this two-week window.

Even when fully heat acclimated, you will run slower paces in higher temperatures. There’s only so much the body can do to prevent a higher heart rate when running in the heat. There’s a reason the best marathon running temperature is in the 40 and 50’s degrees Fahrenheit! If you have a workout that prescribes a certain pace, try running in the morning or inside on a treadmill. Night running is also an option, but you’ll often still encounter residual higher temperatures and humidity from the full day of sun warming. For your easy runs, don’t be afraid to run during the day. You’ll run slightly slower, but once heat acclimated and hydrated, you can still have an enjoyable experience.

See you at the Finish Line!

-George