How to Exercise In the Heat
Learn how to keep cool when you’re exercising in hot conditions.
Ben Greenfield
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How to Exercise In the Heat
If you tuned into the recent New York City Triathlon, you may heard that there were many heat-related illnesses during the race, and even one tragic death. During the 2007 Chicago Marathon, runners were rerouted to a city park and instructed to stop running, since the heat was too intense to ensure runner safety. But even if you don’t plan on doing a triathlon or marathon in hot weather, a high temperature outside or in the gym can make exercise uncomfortable, inhibit performance, cause dehydration, and leave you feeling literally and figuratively under the weather. In this article, you’ll learn how to keep cool when you’re exercising in hot conditions.
What Happens to Your Body in the Heat
As soon as you get into the heat and begin to exercise, you force your body to circulate blood out to the skin, where it can be cooled. But this circulation to your skin can draw precious, oxygen-delivering blood away from your working muscles, and also lower the amount of blood your heart can pump with each beat. In addition, you’re also losing blood volume as you lose fluid in sweat, and this places additional demand on an already stressed heart.
As blood becomes a precious commodity and your heart is forced to work harder, your heart rate goes uncomfortably high, your breathing becomes more difficult, your blood pressure drops, and your core temperature rises. Eventually, you reach a point where your body sends a message to your brain to stop, and at that point, exercise goes from being uncomfortable and difficult, to simply impossible.
How to Stay Cool in the Heat
So what can you do about this loss of blood volume and increase in body temperature? Here are 5 solutions:
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Train your body to maintain a higher blood volume. Also known as “heat acclimation,” training your body to have more blood volume involves consistent training and heat exposure. Gradual exposure to exercising in hot conditions is one of the best ways to achieve heat acclimation. For example, start with 10-20 minutes of jogging, cycling, or brisk walking in the afternoon heat, and add 2-5 minutes each day as the heat becomes more tolerable. Combine this with drinking large gulps of water whenever you feel thirsty to help your body learn to increase blood volume for cooling.
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Increase your sweat rate. Did you know that fit individuals and athletes sweat more? This is an enhanced cooling mechanism developed through heat exposure. A good method for training your body to sweat more is to visit a steam room or sauna for 10-20 minutes. Two to three weeks before a hot-weather triathlon, increasing sauna or steam room time to 45 minutes can help, but be careful as it can be taxing on the body!
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Decrease the amount of salt produced in your sweat. As your fitness and heat exposure increase, you not only sweat more but lose less salt. Your body learns to retain the sodium needed for muscle contractions. During gradual heat acclimation, your body automatically decreases salt production in sweat. Reducing sodium intake during exercise can further train your body to retain more salt, leading to lower salt excretion.
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Increase salt store availability. If planning extended exercise in the heat, such as a marathon or triathlon, consider increasing your salt intake for the few days prior to the event, especially if on a low-sodium diet. Adding extra salt to meals or consuming electrolyte tablets that dissolve in water can provide additional sodium stores to rely on during exercise.
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Keep your core temperature cooler. Of all heat management strategies, this is the most critical since you’ll inevitably get hot. Implementing strategies to cool your core temperature is essential. Some of the most effective methods include:
A) Dump water on your head and face. Whether from a gym fountain, a hose at home, or an aid station during a race, splashing water on your body can facilitate evaporative cooling and provide a refreshing sensation that helps override feelings of overheating. The colder the water, the better!
B) Wear clothing that breathes. Exercise clothing that is designed for hot weather exercise is made of fabric that wicks away sweat and allows for your skin to breathe. A cotton t-shirt will not accomplish this effect, and may make you feel even hotter. Instead, look for synthetic fabrics specifically designed for exercise in hot conditions, such as polyesters, micro-fibers, and even ultra-thin wool.
C) Drink. The best and easiest way to maintain blood volume is to drink water that is as cold as possible whenever you become thirsty. Do not wait until several minutes after you’ve become thirsty to drink. If you have a long run planned, such as when you’re preparing for a marathon, consider carrying a water bottle with you, or running small loops near your house or a park where you can drink water often.
D) Use ice. Not only can ice help keep water cold during warm weather exercise, it can also be shoved down the front or back of your shirt, or, as is my habit during the Ironman World Championships in Hawaii, down the back and front of the legs. In addition, you can chew on ice or drink cold slushies to cool your core, as well as wear specially designed arm cooling sleeves, vests, and gloves!
E) Limit sun exposure. If you’re exercising in the heat, try to stay under trees, near fences, behind buildings, and in as many shady spots as possible, since direct sun exposure can significantly affect your body temperature.
Ultimately, the human body is incredibly able to adapt to hot conditions, but it needs gradual exposure to the heat and adequate water – plus, the strategies I described above for an added advantage..
If you have more questions about how to keep cool during exercise in the heat, share them below in Comments and on the Get-Fit Guy Facebook page!
Woman Jogging image courtesy of Shutterstock
About the Author
Ben Greenfield received bachelor’s and master’s degrees from University of Idaho in sports science and exercise physiology; personal training and strength and conditioning certifications from the National Strength and Conditioning Association (NSCA); a sports nutrition certification from the International Society of Sports Nutrition (ISSN), an advanced bicycle fitting certification from Serotta. He has over 11 years’ experience in coaching professional, collegiate, and recreational athletes from all sports, and as helped hundreds of clients achieve weight loss and fitness success.