Combating the desert heat: Heat acclimation.

heatacclimationHow to Become Heat-Acclimated
by Lynn Bremner –

After moving to the desert year-round, I learned that heat acclimation would be a necessity if I wanted to keep up with my regular outdoor activities during the summer months. My normal activities include running, horseback riding, golf and hiking.  I couldn’t bear an entire summer indoors, so I opted to acclimate and to take on the heat.

Local residents in my new neighborhood seem to stay inside, swim and watch a lot of movies.  This isn’t enough for me as I work at home – getting out of the house is key to my mental health. I started to research running in the heat and learned a lot about heat acclimation.  I bought a hydration waist pack (Camelbak) and started training for the heat!

The Process
It takes healthy people approximately 10 to 14 days to fully acclimate to hot environments. The time it takes to acclimate is longer than most vacations, so be sure to take it easy if you are traveling in areas that are hotter than your average climate at home. The process of heat-acclimation will help your body adjust to the hotter environment. Before you begin, it is important to understand the signs of heat stress, heat stroke and how your body reacts physiologically to the heat.

You want your body to adjust to the following physiological changes . . .

-Sweat rate increases
-Sweat is more diluted
-Heart rate decreases
-Body temperature increases

What happens when you exercise in the heat?
Your body’s core temperature rises during exercise in a hot environment.  This causes your heart rate to increase, your skin temperature to increase and your sweat to become more profuse.  These actions make your heart work harder.  Your body pushes the blood to the surface of your skin to cool before it sends it to your heart and then on to your muscles.  This is why we become so flushed and our cheeks get red when we get hot.  As your body heats up it has to work harder to cool your blood and keep your muscles working.

Your body also loses fluid when you sweat, and you can easily become dehydrated.  Athletes can lose from 1 to 2 liters of body fluid by sweating during a 1-hour workout.  If you lose more than 2% of your body weight through dehydration you will start losing your ability to perform physically.

Getting Started
Start slowly and go at a pace that feels comfortable to you.  Everyone has a different tolerance level, so make sure you pace yourself accordingly. Start with 10 – 15 minutes of exercise at a time or less.  You can start by walking instead of running.  Once you get used to walking in high temperatures you can add in some running.  Gradually increase the amount of time you are running vs. walking.  Over a period of two weeks, slowly increase the amount of time you are exercising.  Your body must adjust physically to the demands created by higher temperatures.

If you are not a runner, you still need to heat-acclimate to golf, walk or bike outdoors in high temperatures.   Just remember to begin slowly and work your way up to the activity you are training for.

It helps to spend more time outdoors.  Just walking to the mailbox, or spending 15 or 20 minutes outdoors while watering your plants or sweeping your driveway will help with the process.  Participating in simple tasks outdoors will help you adjust better to the heat.

What is your hydration plan?
Develop a hydration plan before, during and after your workouts.  Some walkers/runners plan their route to pass by public facilities with water fountains. Or they may stash water along their route so they don’t have to carry it.  This takes some planning.  Hydration packs designed for walking, hiking and running are available at most outdoor or sporting goods stores.  In the summer I wear a special CamelBak waist pack designed for hikers and runners.  This particular pack is called the “Alterra” and can carry .8 liters of fluid. It weighs 2.66 lbs when full.   CamelBak is one of the better-known hydration systems for outdoor activities.  Whatever you choose for your water needs, make sure it can carry enough fluid for the duration of your outdoor activities.  Research hydration packs and read reviews on them to make sure they are compatible and comfortable for your chosen activity. I discovered the Alterra Pak by researching reviews on the Internet written by runners. Most found the Alterra by CamelBak to be the most comfortable one available.

Water vs. Energy Drinks?
Energy drinks have sugar and electrolytes that help fuel your muscles and reduce sweat loss.  People also tend to drink a lightly flavored energy drink in greater quantities than plain water, a good reason to plan to consume liquids like Gatorade. You can drink a combination of both water and a flavored energy drink.  The key here is to drink enough liquid to stay hydrated, and energy drinks help achieve this goal better than plain water.

It is VERY common to underestimate how much fluid you lose when you sweat.  Dehydration happens too easily and we need to make sure we prepare and replace the fluid loss by drinking water or energy drinks before, during and after exercise in a hot environment.

Drink fluids early and often.  Don’t wait until you are thirsty to take a drink.  If you drink only when you are thirsty, you may already be on your way to becoming dehydrated. Even mild dehydration can increase your core temperature.  The goal is to keep your body temperature lower, so hydrate more.  It will help.

Tips to avoid dehydration

-Drink more water and fluids per hour than you think you need (1 liter per hour or more as needed during exercise).
-Consume potassium rich foods such as bananas, etc.
-Add salt to your diet to help your body store water better.
-Cover your skin with light-colored, lightweight, loose long sleeves and pants when appropriate.
-Wear a hat to keep the sun off of your head and face.
-Splash cool water on your head or wet your hat during workouts to cool your core temperature.
-Wear sunglasses to protect your eyes.
-Avoid the hottest part of the day (10 – 3 PM), unless you are heat training.
-Take breaks in the shade.

Warning Signs of heat stress
Overheating can cause fatigue, dizziness, nausea, cramps and vomiting.  If you start feeling any of these symptoms stop or slow down your exercise and rest in a shady area if possible. Hydrate and rest so your body temperature can reduce itself to a more normal level. Seek medical attention if you continue to feel ill.

Heat Stroke – A very serious condition
Be very aware that heat stroke is a life threatening condition. It can be fatal if not treated promptly. Heat exhaustion often precedes heat stroke. Signs of heat stroke are high body temperature_, the absence of sweating, with hot red or flushed dry skin, rapid pulse, difficulty breathing, strange behavior, hallucinations, confusion, disorientation, _and finally seizure and coma. If you or someone you are with shows signs of heat stroke, get to the shade, spray with cool water, and apply ice packs to the armpits or groin area. Call 911 immediately.

Staying acclimated
You can just as easily lose your acclimation to heat if you stop exercising.  You lose a day of acclimation for each day you don’t exercise.  After a couple weeks of no exercise you will need to re-acclimate yourself all over again. Illness and alcohol can slow the process of acclimation and may also cause overheating even when you are acclimated.

10 thoughts on “Combating the desert heat: Heat acclimation.”

  1. Vitamin C helps in hydration. I take it before and during desert hikes, most of which are in and around the Tularosa Basin of southern New Mexico. During the Bataan Memorial Death March (walking marathon) in the Tularosa on White Sands Missile Range, each 3 miles they pass out small cups of water, electrolyte, and orange and banana sections and those always help a lot, especially in the heavy division, carrying a 35-pound load.

  2. When motorcycle racing I always began hydration at least one and preferably two days before. I suspected this let the cells hydrate fully prior to the exertion.

  3. linda n charlton

    I tell everyone that the water you take with you, when itis 1/2 gone, turn back because the water that is left will get you back to where you started.

  4. I am an experienced Ironman and all World athlete and I can advise you that drinking sports drinks does not hydrate you anywhere near as well as water. The sugar in sports drinks actually dehydrate your body and draws water into your stomach and slows the entry of water to your body. There are no water is coming onto the market which actually increase the rate of hydration as I have done some testing with one of them which made me actually want to hydrate when I drink it. It was slightly alkaline pH 8.4, mineral balanced, and antibacterial as well as in contained antioxidants,

  5. James Scharnberg

    I am an over 40 disabled veteran, bad joints and all, and have recently (approx 6 mos. ago) moved from Indiana to southern California (outskirts of the Mojave desert). As the drier air et al seems to be HELPING, moderately, my DJD/DDD, I have decided to attempt to get back into shape, other than round. Any advice would be very much appreciated.

  6. Very useful advice, thanks. I’m spending a few months in Vegas, and it’s hot as hell here, but don’t want to stop my daily jog.

  7. Yes, 0.08 liters is not much, but it is fine for a 1 hour walk for me or a short run that lasts about 1 hour or less. I don’t go running when it is hotter than 109 F, it is just too hot for me. The reason I chose that particular water pak is because it is super comfortable and it suits my particular hydration needs. Thanks for the note.

  8. Good advice in general, but 0.8 litre of water is ridiculously low. That would not be adequate for an hour’s walk in the heat of the day. General recommendations are for a gallon/day, and in my experience, that is a conservative estimate. Also, acclimation studies for the military indicate that humans will not maintain adequate hydration if they have only water to drink. Adding a bit of sweet flavoring usually assures compliance. Finally, the American diet has so much salt in it that additional amounts only add stress to the kidneys, and should be avoided.

  9. I live in the high desert of California, and I’ve lived here all of my life, it gets so hot that sometimes I even feel like I haven’t acclimated to the heat. When people stay hydrated, its dangerous when they drink too many sports drinks. You want some that have electrolytes, have SOME of this, but really what your body needs is water.

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