By Dr. Mercola
As summer temperatures rise, you may be hit with conflicting drives. On the one hand, the outdoors beckon more than ever, yet the very thought of exercising in the heat may make you weak just thinking about it.
As stated in the featured article1, exercising in heat requires a period of acclimatization—generally about two weeks. Once your body has adjusted to the heat, you will start to sweat sooner, and your sweat will be more diluted than before. Furthermore:
"There will be a lower risk for dehydration and a reduction in the heat gained through exercise that will help maintain a lower core temperature and heart rate response...
[A]s much as 25 percent of the healthy population is estimated to be heat intolerant in an unacclimated state. Once they get acclimated that drops to two percent."
If you're following my Peak Fitness program with high intensity interval training, you may want to avoid doing the Peak exercises during a heat wave until you're fully acclimatized to the heat. The same goes for long-distance runners, who may need to adjust their performance expectations as the temperatures rise. According to exercise physiologist and running coach Tom Holland, quoted in the featured article2:
"Running in heat is difficult, because blood has two conflicting interests - supplying working muscles and going to your skin to cool your body down. So there is less blood for the muscles, your heart has to work harder, your heart rate increases, and the relative intensity of the run increases. You simply cannot run as fast in hot conditions."
Exercising outdoors during the summer sun with maximum skin exposure can be one of the healthiest strategies I can think of, as you're not only getting exercise, but also plenty of sunshine, and if you take the advice to go barefoot, plenty of beneficial negative electrons through the soles of your feet as well. I'll discuss this more below. Woman's Day magazine3 features an article with 13 helpful tips to "beat the heat" and prevent heat-related problems during your summer exercise. I've included some of their best advice here, along with a few tips of my own.
10 Warm-Weather Workout Tips
- Dress appropriately. Loose-fitting polyester/cotton blend clothing or other fabrics designed to wick away moisture will help keep your body cooler. It's not sweating itself that cools your body, but rather the evaporation of sweat. So avoid wearing clothing that soaks up sweat but doesn't allow it to evaporate.
- Stay properly hydrated. The more you sweat, the more you'll need to rehydrate to avoid heat cramps, exhaustion, or worse, heat stroke. Make sure to carry a bottle of water with you, and drink often. You're better off drinking a small amount more frequently than downing a lot of water all at once.
Avoid sports drinks and other sugary beverages though, as these will do you more harm than good. For those of you who are exercising to lose weight, you should also know that sports drinks are usually anything but low calorie. There is a perverse irony of people who are working hard exercising to burn off calories, only to be slurping down more calories and HFCS, which is linked to obesity, while they're working out.
If you exercise for 30 minutes a day, at a moderate intensity, water is the best thing to help you stay hydrated. It's only when you've been exercising for longer periods, such as 60 minutes or more, or at an extreme intensity, or on a very hot day or at your full exertion level, that you may need something more than water to replenish your body.
To replace electrolytes lost from profuse sweating, opt for coconut water instead, which has one of the highest sources of electrolytes known to man, and can be used to prevent dehydration from strenuous exercise or even diarrhea. Be careful to restrict the coconut water to times when you are sweating profusely only, as there are plenty of sugars in coconut water, which can be a problem if you are consuming them on a regular basis when you are not sweating.
Electrolytes are inorganic compounds that become ions in solution and have the capacity to conduct electricity. They are important for electrical signaling—and of course your brain, heart, muscles and nervous system are all bioelectrical systems. Your cells use electrolytes to maintain voltage across their membranes and carry electrical impulses to other cells. Things like water and blood pH depend on your body's proper electrolyte balance, and you can suffer severe medical problems if your electrolytes fall out of balance.
Alternatively, make your own sports drink by mixing some lemon or lime juice with water along with a pinch of unprocessed, natural salt, such as Himalayan pink salt, which contains more than 80 different trace minerals your body needs.
- Time your exercise to avoid peak heat. As stated in the featured article, sun, humidity and pollution levels are most intense during the midday, so to minimize the effects of the heat, work out either first thing in the morning, or in the late evening.
- Protect your skin. While the featured article dispenses the conventional advice to apply sunscreen before heading outdoors, I strongly disagree with this recommendation. Not only are you forfeiting the benefits of vitamin D production in your skin, you're likely slathering on toxic and hormone-disrupting chemicals that will transfer directly into your blood stream.
Instead, I take a daily astaxanthin supplement, which acts as an internal sunscreen and skin protector. Many athletes complain of feeling ill from overexposure to the sun after long training sessions outside. However, many report astaxanthin has allowed them to stay in the sun for longer periods of time, without feeling ill and without burning. Besides copious testimonials and anecdotal evidence, scientific studies have substantiated these skin protective effects. If you decide to give astaxanthin a try, I recommend starting with at least 2 mg per day. I have been taking 8 mg per day for the past couple of years and I can't remember the last time I was sunburned. Another common-sense strategy to protect your skin is to wear a light-colored, loose-fitting, long-sleeved shirt and a cap.
- Go slow until your body has acclimated to the heat. Start slow, exercising in the heat for just a few minutes at a time, and gradually increase the amount of time as your tolerance builds. Again, signs of increased tolerance include breaking into a sweat more rapidly, and your sweat being more diluted or watery.
- Seek shade. Exercising in shady areas, such as tree-lined trails and parks, will help you stay cooler when the temperature rises.
- Head toward water. Any kind of water exercise is an ideal choice on a hot day as water naturally cools your body. While most city- and suburb-dwellers may opt for a pool, your best alternative would be swimming in a lake, ocean, or other natural body of water, to avoid hazardous pool chemicals. An added boon of that is that you'll naturally ground yourself, as long as you're barefoot.
One of my all-time favorite exercises is to go in the ocean with 2-4 foot waves and body board. Not only is this a great way to get sun and vitamin D but there is also the negative ions from the ocean and all the benefits of grounding. You also don't have to worry about cooling down as the ocean does a pretty good job of doing that for you.
- Take off your shoes. Surprising as it may sound, emerging research suggests modern running shoes, with their heavily cushioned, elevated heels, may actually encourage runners to strike the ground with their heel first—a move that generates a greater collision force with the ground, leading to an increased potential for injury. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may actually protect your feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.
While much of the debate between the barefoot and the shoed-foot focuses on the potential for injury, another often overlooked aspect is the health benefits of grounding.
The technique of grounding, also known as earthing, is simple: you walk barefoot to "ground" with the Earth. The scientific theory behind the health benefits of walking or running barefoot is that your body absorbs negative electrons from the Earth through the soles of your feet. The grounding effect is, in my understanding, one of the most potent antioxidants we know of. These antioxidants are responsible for the clinical observations from grounding experiments, such as beneficial changes in heart rate, decreased skin resistance, reduced blood viscosity, and decreased levels of inflammation.
The ideal location for going barefoot is the beach, close to or in the water, as sea water is a great conductor. Your body also contains mostly water, so it creates a good connection. A close second would be a grassy area, especially if it's covered with dew, which is what you'd find if you exercise early in the morning. Concrete is a good conductor as long as it hasn't been sealed. Painted concrete does not allow electrons to pass through very well. Materials like asphalt, wood, and typical insulators like plastic or the soles of your shoes, will not allow electrons to pass through and are not suitable for barefoot grounding.
- Remember these quick cool-off tricks. Some simple tricks to help you cool your body down include:
- Running cold water over your forearms will help reduce your body temperature. Many public areas have drinking fountains or public rest rooms where you can do this.
- Using a spray bottle, spray cool water on your skin while fanning air on it—either with a small portable fan, a paper fan, or even a towel or piece of clothing. As the water evaporates, your body temperature will drop.
- Apply an icepack or cooling neck wrap to your neck, forearms, groin, and/or armpits.
- Team up for safety. Symptoms of heat exhaustion can come on quickly if you're not paying attention, and since fainting is one of the symptoms, it can be far safer to exercise with a partner when the heat is on. (Other warning signs and heat-related symptoms will be reviewed below.)
Signs and Symptoms of Heat-Related Problems
Remember to listen to your body. If you start to feel dizzy, faint or nauseous, stop your workout immediately. This is not the time for fitness bravado; pushing yourself to extremes. Leave that for some other time when potentially life-threatening side effects are not involved. In fact, if you know you're not acclimatized to the heat yet and the temps spike into the 90's, you may want to consider bringing your exercise indoors—especially if you're doing high intensity exercises.
Heat exhaustion and heat stroke are your primary concerns, so make sure you stay alert to the warning signs. The first sign of trouble usually presents itself as heat cramps—usually in the stomach, arms or legs. Treat heat cramps by:
- Drinking water and/or coconut water for electrolytes, and
- Resting in a cool, shaded or air-conditioned area. The cool-off tricks listed above will further help to reduce your core body temperature
Ignoring heat cramps can quickly progress to heat exhaustion, the signs and symptoms of which include:
Headache Dizziness, lightheadedness, fainting Nausea and/or vomiting Muscle cramps Fast, shallow breathing / Weak or rapid pulse Cool and clammy skin; chills
Heat exhaustion is treated in the same manner as heat cramps. Your number one concern is to lower your body temperature and rehydrate your body. If symptoms persist, you should seek immediate medical attention, as heat stroke is a serious condition. Symptoms of heat stroke4,5, the worst case scenario, are:
High body temperature / fever: A body temperature of 104 F (40 C) or higher is the main sign of heatstroke Flushed skin: Your skin may turn red as your body temperature rises Lack of sweating Shallow, rapid breathing Nausea and/or vomiting Strong, rapid pulse: Whereas your pulse may have weakened during the initial stages of heat exhaustion, your pulse may now significantly increase in strength as heat burdens your heart to help cool your body down by increasing circulation Throbbing headache Confusion Loss of consciousness (including deep coma) Rigid or weak, limp muscles, as initial muscle cramps progressively worsen
IMMEDIATE action and medical attention is needed when signs of heat stroke are present, which is why it's good to have an exercise buddy with you. Call for medical attention, and then take immediate steps to cool down while waiting for emergency responders to arrive:
- Help the overheated person into a shaded area and remove excess clothing.
- Place ice packs or cold, wet towels on the person's head, neck, armpits, forearms and groin.
- Mist the person with water while a fan is blowing on him or her, or use any available material to fan air.