Summer’s a good time to catch some sun while putting in a good workout. But as temperatures rise, taking care of your body while running, hiking, biking, or doing some high-intensity interval training (we see you, Rose City Rec Room at Abernethy Elementary School—more on them later) can prove a little more difficult. (And when the weather breaks 100, as we saw during the Pacific Northwest heat wave, exercising outdoors isn't advised at all.) Hot weather means extra stress on your body and increased heart rate and body temperature during your workout. If you're not careful, you could push your body down the path of a heat-related illness and further away from your fitness goals.

So what are the best ways to stay active and safe during the summer swelter? Here are some tips for before, during, and after your workout. Plus, how to recognize heat exhaustion and heat stroke.

Stay Light and Hydrated

Water is your best friend always, and especially during the summer. Your water needs will vary depending on your activity level and geographical location, but the National Academy of Medicine (formerly the Institute of Medicine) recommends a daily total of 3.7 liters (15 cups) for the average adult male and 2.7 liters (11 cups) for the average adult female. 

Depending on the intensity and length of your workout, consider switching to a sports drink. Sports drinks tend to have added electrolytes like potassium and sodium that can help replenish your body and relieve muscle cramping.

Choose your clothes wisely when heading outdoors too. Wear light, loose, clothes made with nonconstrictive and breathable materials to allow your body to cool down properly.

Start Low and Go Slow

“Always approach your exercise routine in the heat with the adage of ‘starting low and going slow,’” says Michael Chen, district medical director for One Medical Portland, a membership-based primary care practice.

Chen suggests starting at a lower intensity and slowly building up as you go. “Don’t push too hard, and give yourself enough water breaks and cooldown periods to let your body adjust slowly, if needed. If you start feeling short of breath, lightheaded, or dizzy during your workout, that is your signal to stop and consider switching future workouts to an indoor setting.”

Switch It Up

Exercising generates internal heat, and our bodies start to work overtime to rid ourselves of that heat by sweating and pushing blood toward our skin. Hot weather adds an extra barrier to our body’s natural instinct to cool down. The easiest way to avert these conditions is to take your workout indoors, but if you need to keep it outside, consider changing things up a bit.

Rather than taking up an hour or so on your evening jog, consider interval training or circuits, which allow for more rest, easier cool down, and more water intake. Aim for shaded areas on your run and listen to your body. If you’re feeling nauseated, fatigued, or cramping up, drink some water and head indoors.

Take It Indoors

There’s no shame in taking the workout indoors if you’re able. Chen says for those who have indoor exercise equipment, such as a treadmill, an elliptical, rowing machines, or something else located in an air-conditioned and well-ventilated space, “this is the perfect time to stay active daily with these options during the summer heat.”

For those who don’t have exercise equipment, Chen recommends the 7-minute workout routine, which only requires a chair to be able to accomplish a clinically proven, cardiovascular workout indoors.

Focus on Restorative Fitness

It's not always about going hard on your workout every single day. “It’s more important for [my members] to listen to their body and take rest [if they need to]," says Shawn Hudson of Rose City Rec Room, a Southeast workout group that does high-intensity training outdoors. "I’ve worked out when it’s freezing cold, and I’ve worked out in CrossFit boxes on the East Coast in the middle of summer when there’s no AC, and there’s just a giant fan, and you’re sweating buckets. One thing you learn is, while you may be pushing yourself hard, that idea of intensity is all relative to that day.”

On days when the weather breaches the high 90s, Hudson says he might adjust his workout to include slightly more time between intervals, or even calling off his workouts entirely, encouraging his members instead to focus on options that promote restoration and recovery. On a day when it's particularly hot, consider swapping the workout for restorative fitness like stretching, using a foam roller, or even getting a massage. “There are different ways to take care of your body when it comes to wellness," Hudson says. "If there’s a day where you can’t workout and you can’t go super hard, there are still good things you can do for you body and feel good about what you did that day.”

Don’t Skip the Cooldown 

Suddenly stopping your workout impacts your body and its natural cooling system (and could lead to an exercise-related collapse—more on that later). Doing a cooldown lessens these impacts. Try walking after a run or light cycling after a strenuous bike ride. It’s even better if you’re able to move to a cooler environment while you cool down.

Another suggestion from the experts is to hop into a cold lake, creek, or shower, because getting wet helps cool you down quicker, and taking a light swim is a great cooldown activity. “Starting with a cool shower to reduce inflammation is generally best followed by a hot shower to help with muscle tension and improving blood flow,” says Chen. 

After you finish your cooldown, drink something cold. Water is recommended as well as coconut water, chocolate milk (yes, really), and low-sugar sports drinks. Avoid sugar, caffeine, and alcohol because they are dehydrating. Having a snack is also suggested, especially something rich in carbs and protein. Carbs are important for the body’s energy levels, while protein helps repairs and rebuilds muscles.

Recognize Heat-Related Illnesses

Heat cramps are involuntary muscle spasms and contractions that occur when exercising in a hot environment, and are typically attributed to fluid and electrolyte loss. Drink fluids and practice a gentle range-of-motion stretches. Painful, but will go away with time and your body temperature may still be normal.

Heat syncope is a fainting episode or sense of dizziness caused by high temperatures, and often occurs after standing for a long period of time, or standing too quickly after sitting or lying down for a long period of time. Exercise-associated collapse, often experienced in long-distance runners, is when you’re unable to stand or walk as a result of lightheadedness, faintness, or dizziness, and usually occurs if you immediately stop running and stand after a race or a long run.

Heat exhaustion is when someone feels sick due to loss of salt and water from heat exposure. People may feel their heart racing and be nauseated, sweaty, or weak, but their body temperature usually stays below 104 degrees Fahrenheit (40 degrees Celsius). Getting into an air-conditioned space, covering yourself with damp towels, taking a shower, and drinking plenty of water are all steps you can take before seeing a medical provider.

Heat stroke happens when your internal temperature exceeds 104 degrees, at which point your body is overheated and you need emergency medical treatment. “Heat stroke can’t be solved with a home remedy,” Chen warns. “A medical professional will help cool your body to a normal temperature with a cold-water bath, ice packs, a cooling blanket, or an evaporation technique to cool the skin.”

If left untreated, heat stroke can cause significant damage to the brain, heart, and kidneys. The longer treatment is delayed, the worse the damage can be. It’s important to recognize heat stroke symptoms so you can seek immediate medical treatment. 

• A body temperature of 104 degrees Fahrenheit (40 degrees Celsius) or higher
• Changes in your mental state or behavior including confusion, slurred speech, agitation, or seizures
• Nausea or vomiting
• Changes in how you sweat: If hot weather is the cause of heat stroke, your skin will feel hot and dry to the touch. If it’s brought on by strenuous exercise, your skin may feel moist.
• Flushed skin
• Rapid or shallow breathing