For a few splendid weeks following winter’s last frost, the mild temperatures and nice weather made exercising outdoors seem oh-so-irresistible. But now the temperatures are starting to go up. What gives? Does this mean you have to go back to indoor workouts? Not at all! It’s still possible to have safe, healthy outdoor workouts all summer long—at least, most days—as long as you practice a little bit of caution.
Your Body’s Cooling Mechanisms—And Their Limits
The human body has an amazing ability to cool itself off. The problem is that when it’s working so hard to keep itself cool, that can affect its ability to perform other functions. And if the heat gets too high for your body to combat, then you’re in trouble.
You’ve probably heard before that sweating is your body’s way of keeping itself cool. As soon as your brain detects that your body temp is getting too high, it sends a signal to your sweat glands to start sending sweat out your pores, where the air evaporates it. This evaporation is what cools you off.
But you do have limits. If it’s a humid day, the wetness of the air prevents sweat from evaporating off your skin, so you don’t end up cooling down as efficiently as you normally would. Then your body temperature ends up going even higher. Additionally, when you’re losing so much fluid through sweating—as well as vital nutrients like sodium and potassium—you run the risk of dehydration and fluid imbalance.
Other natural cooling mechanisms can create problems as well. Increased blood circulation to the skin, which helps keep you cool, means there’s less blood available for your muscles. This makes your heart start to beat faster, and you risk suffering heat exhaustion and heat stroke.
So How Do I Stay Safe?
Any sort of plan for healthy exercise should always start with consulting your doctor. While most healthy people will be able to exercise in the heat, your doctor is the one who can provide insight into what’s smartest for you.
Here are a few of the best heat-related practices you should incorporate into your workout routine this summer
- Start by checking the weather before every workout, including the heat index and the humidity levels. Most experts encourage caution when it’s 80–90 degrees and extreme caution when it’s 90–100 degrees. Anything in the triple digits puts you in danger—those are the days when you should move your exercise indoors.
- Keep to the shade and seek out green spaces like your local park. Concrete, especially blacktop, absorbs a lot of heat, so temperatures will be higher when you’re surrounded by buildings.
- Work out in the early morning or in the evening when temperatures are lower. Be sure to use reflective gear if you’re going out when it’s dark.
- Wear loose-fitting, lightweight clothing in light colors. While moisture-wicking fabrics commonly found with athletic apparel might feel great, the American Council on Exercise recommends plain cotton because it will soak up the sweat and keep your body cool as the air around you dries the damp material.
- Stay hydrated by drinking a pint of water beforehand and stay hydrated throughout your workout by drinking eight ounces every 20 minutes. Your body will absorb plain water faster than it will sugary sports drinks like Gatorade.
- Don’t forget that heat tolerance is relative and very personal. What’s not too hot for a friend might be too hot for you, especially if you’re at different fitness levels. Allowing yourself to acclimate to new temperatures by starting a fitness routine in the spring or early summer will ensure you’re better suited to high temperatures than you would be if you tried to start exercising on an extremely hot day in July or August.
Recognizing Signs of Heat Stroke
If the idea of suffering heat exhaustion or heat stroke sounds scary—well, it is. Heat stroke can be a life-threatening emergency, and anyone who’s doing intense physical activity should be aware of the signs.
Heat-related illness will usually start with heat cramps; when you feel moderate to intense pain or spasms because of muscle contractions brought on by the heat. If your body temperature continues to rise and reaches 104 degrees Fahrenheit, you can suffer heat exhaustion, marked by nausea, vomiting, headaches, and weakness.
When your body temperature exceeds 104 degrees, then you can suffer heat stroke. Your body temperature is now so high that, in addition to fatigue and nausea, you will have rapid breathing and heart rate, and you could feel confused, irritable, or dizzy. You might have vision problems or slurred speech.
If you or somebody you’re with is potentially experiencing heatstroke, you need medical attention immediately to prevent damage to brain, heart, or other vital organs. While you wait for emergency assistance, move to a cool place inside or in the shade and try to cool down with fans, damp washcloths, or a drink of cold water.
Oh, And One More Thing: Sweating Doesn’t Burn Calories
Some people think exercising in the heat is better for their fitness efforts because they’ll just sweat away excess weight—and while that’s technically true, it’s going to be mostly water weight, not fat.
Yes, it does take some cardiovascular effort to cool your body down when it’s hot outside, so there might be a slightly increased caloric expenditure above exercising at a comfortable temperature. But not enough to make a significant difference.
If you weigh yourself after an outdoor workout and see that you lost a few pounds, it’s not because you burned off fat (remember, it takes a deficit of 3,500 calories to lose 1 pound of bodyfat). Instead, that’s just the weight of all the water that has left your body via perspiration. Be sure to replenish those fluids by drinking two glasses of water for every pound you lost.
Let summer be a time for enjoying the outdoors, but don’t force yourself if it’s making you miserable or if you’re stressed about heat safety—exercise should be an enjoyable activity! If you find the idea of going outside turns you off from exercise, then it’s best to stick to indoor workouts with your treadmill, elliptical, stationary bike, or weight room.
