How to Exercise in the Heat and What to Do if You Get Sick

US News

The idea of a summertime jog could send some running (or rather driving - with icy lemonade in hand) for the hills. Why punish yourself outdoors when the modern marvel of air conditioning is installed in most gyms? Others thrive in the 90 degree heat, appreciating the extra sweat, sunshine and fresh air.

Even if you relate more to the first group, an occasional outdoor workout can be the perfect way to mix up monotonous gym routines. Don't limit yourself to the elliptical - or worse, the television - because you're scared of a little summer heat. Safely enjoy (or a least try) hot weather workouts with the tips below:

Acclimate. Humans are like tropical animals, and we can adapt quickly to heat stress, says Michael Sawka, an adjunct professor in the School of Applied Physiology at Georgia Institute of Technology. But it might not feel like that at first. "When you go out for the first time in the summer heat, you're going to have a lot of cardiovascular strain, you won't be sweating as much and you may feel pretty miserable," says Sawka, also a former chief of the Thermal and Mountain Medicine Division at the U.S. Army Research Institute of Environmental Medicine. "But as you go out over a number of days - let's say a week or two - you'll find that you adapt very quickly ... you can go out in the heat and have less physiological strain."

While that early June jog may have left you heaving, don't give up. Tone down the intensity and duration a bit, and weave in several breaks, but continue regular outdoor workouts so your body becomes better at handling the heat. As your heat tolerance improves, start rebuilding your workout intensity to where it was on those glorious 70 degree afternoons.

Hydrate. While sweat may be the bane of your underperforming deodorants, it's crucial for keeping you cool and safe during exercise. Work out hard for an hour, and you may lose about a quart of water in sweat, so load up on fluids. "Your body's ability to combat heat stress is based on what it has in it to do so," says Kenny Boyd, athletic trainer for the University of Texas Longhorns football team - no strangers to grueling workouts in the Austin heat. "Make sure that you're adequately fueled through what you're eating and drinking."

And how much "fuel" is adequate? About 20 or 30 minutes before your workout, drink 8 to 12 ounces of water, and tack on another 6 to 10 ounces for every additional 30 minutes of exercise, writes Gordon Blackburn, director of the Cleveland Clinic's Cardiac Rehabilitation, Preventive Cardiology and Rehabilitation Program, in a post for the hospital's website. (For more about what to eat before and after workouts, check out this Eat + Run blog.)

Instead of just drinking when you're thirsty, consume water throughout the day, as well as water-rich foods, like fruit. If you're planning to exercise intensely for more than an hour, consider a sports drink, which may help replace sodium, chloride and potassium, Mayo Clinic suggests.

Consider the time of day you exercise. Boyd's football team practices at 7 a.m. and 7 p.m. to avoid the worst of the Texas sun. You, too, should opt for workouts in the early mornings or evenings when the heat is less intense.

Dress appropriately. Lightweight, loose-fitting clothes help sweat evaporate, according to the Mayo Clinic, so go for light-colored cotton T-shirts, shorts and, if possible, brimmed hats. And don't be shy with the sunscreen.

Take it inside. We're all for challenging workouts and sweat-fests, but if you're concerned with your health, bring it indoors. Shorten your time in the sun by perhaps stretching, warming up and cooling down inside and doing only the core of your workout outside, Boyd suggests. Or bring the whole routine inside. Even if you don't have a gym membership, numerous exercises can be done anywhere, such as yoga, bodyweight strength training and simply running up and down the stairs.

And what if you didn't quite follow these tips, and the summer heat gets the best of you or your workout buddy?

Well, you might get sick. Certain people are more prone to serious heat illness, as listed in a 2011 Goldman's Cecil Medicine textbook chapter co-authored by Sawka. Particularly young and old people, as well as those who are dehydrated, have excess body weight or have a low level of physical fitness are predisposed. If you have certain health conditions, like a fever or viral infection, or are simply not acclimated to the heat (hello, first tip listed above), then you're more at risk, too.

Sawka lists a few issues you may encounter, in order of increasing severity: heat exhaustion, heat injury and heatstroke. The majority of incidences wind up being heat exhaustion, which people can recover from quickly, Sawka says. Often, this heat exhaustion is confused with heatstroke, and that's just fine, because, as he suggests, "Any time you have a heat illness, you should think of the worst, and be aggressive in treating that person."

So if you or a fellow exerciser is feeling the warning signs of heat illness, which Mayo Clinic identifies as nausea, headache and dizziness, among others, then get aggressive:

Cool off. Stop exercising, find shade, remove unnecessary equipment and clothes and, if possible, stand in front of a fan to improve evaporation of sweat. Boyd's overheated players have access to a tub of ice water - the "gold standard," he says - and both he and Sawka agree that immersing limbs or the whole body in cold water is a crucial step. This action helps reduce body temperature and cool the skin, which forces blood from the skin back to the heart to reduce cardio strain, Sawka says.

Rehydrate. Drink plenty of water as you're cooling off and throughout the following 24 hours to correct your dehydration. However, stop yourself before instinctively shot-gunning a bottle of Gatorade. The Goldman's Cecil Medicine chapter says when managing heat illness, "Rapid overcorrection of serum electrolytes (e.g. sodium) should be avoided."

Call a doctor. If you don't feel better within 30 minutes, call a doctor, Mayo Clinic suggests. Again, with heat illnesses, it's best to assume the worst. In this case, the worst is heatstroke, which can result in brain damage, organ failure and even death. Make the call so you're well enough to exercise during another steamy summer day.

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