Gotta’ Run: Smart exercise in heat and humidity

Published 8:13 pm Monday, June 22, 2020

Last week’s column about my struggle with dehydration during heat and humidity generated considerable response. This issue can derail nearly everything we do including overall health. The very worst dehydration issues for regular exercisers are increased by heat and humidity. So, what can we do to keep exercise going from May through early September? 

With summer in full effect, I have noticed my runs have begun to feel different. What should be an easy pace now sometimes feels like running in mud and working harder to get nowhere fast. The warmer the weather, the harder your body has to work to keep cool. Your heart rate will be higher and breathing more difficult. The reason why is your body is directing blood to the skin to cool you off through sweating. That means there’s less blood available to transport oxygen to your muscles. What would usually be an easy-paced run often feels more like a max all-out effort.

Just this last week had two extremes for summer running. We had more of the previous week’s heat and humidity, and we have a couple of strangely cool days with rain. My own running results followed the temperature, but with higher temps the humidity becomes the culprit too. 

Here are a few things we can do, garnered from 40 years of experience, to make outside exercise a little bit more comfortable during the next few months. Most of us have had enough of being inside already. 

Morning temperatures are usually the coolest during the summer. It also will give you a break from the strongest hours of sunlight. The humidity can sometimes be high in the morning, but at least you won’t see the blazing sun. And you may even get the treat of a gorgeous sunrise. You want to be sure to avoid the middle part of the day, which will be the hottest. Some science supports that strong sunshine cuts time to exhaustion by half. 

Wear as little clothing as legally possible. If you are the sports bra only or shirtless kind of person, do that. Stick to light-colored, loose, wicking materials. Now is not the time for wearing all black or cotton. No matter what fabric you are wearing, Body Glide works for preventing chafing.

 Some runners use sunscreen even for early runs or late runs since the summer days are brighter early. Just be sure it’s sweat proof, avoiding the pain of sunscreen and sweat in their eyes. A hat or visor will not only protect your skin from the sun, but it will also help to keep your face shaded while making a rainy run more fun. Soaking the hat or visor in cold water before heading out the door can help to lower body temps to feel cooler.

We should start off slower than during the cool days. You’ll want to gradually increase your heart rate rather than starting out too fast. Same thing for the end of the run. Consider a gradual slow-down that includes some time for a moderate walk. It will help regulate your heart rate and cool your body a bit. With most of my individual running clients, we include a relaxing and contemplative walk at the end of the workout. 

A short revisit to hydration includes a couple things I should have added last week. Hydration is one of my favorite subjects with lots of theories on how much water we need. My all-time favorite is a simple one; half the body weight daily in ounces. For a person who weighs 150 pounds, they need a minimum of 75 ounces of water daily, not counting how much you add for exercise. Drink up until thirst disappears afterward. Start your exercise hydrated, because another rule of thumb says you will never catch up while working out. 

The American College of Sports Medicine says any high intensity sporting event with a temperature above 82 degrees should be canceled so it’s OK to back off a little. 

Your outside exercise results will change as a function of how hot and humid it is, your degree of effort, and how you’re dressed. But highest among all of these remains hydration. Get it right and summer exercise can be done!

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