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Aug 10, 2023

Running in Humidity: Tips for Making it More Bearable

We earn a commission for products purchased through some links in this article. Why Trust Us? Cold showers, sponges, and more expert-backed strategies for surviving the summer weather. Running in

We earn a commission for products purchased through some links in this article. Why Trust Us?

Cold showers, sponges, and more expert-backed strategies for surviving the summer weather.

Running in humidity can be a serious slog: the thick air, the unrelenting moisture, the fact that everything feels a million times harder.

When combined with hot temperatures, humidity can make running downright miserable. Unfortunately, this combination is unavoidable for many athletes across the U.S., especially during summer.

The good news: While you can’t control the weather, you can take steps to better handle it. We tapped three experts to learn why humid runs can tank your performance, plus simple things you can do to make your muggy runs more bearable.

Let’s start with a quick physiology lesson. When you run, your body tries to maintain its temperature by sweating. Specifically, “it’s the evaporation of sweat that cools us,” Amity Lui, MS, RD, a distance runner and New York City-based sports dietitian explains to Runner’s World.

Humidity—the villain in this story—can screw with that cooling process. That’s because humidity is a measure of how much water vapor is in the air, so in high humidity, the air is “jam-packed with water vapor,” says Lui, which prevents your body from being able to effectively cool itself since there’s no more space in the air for your sweat to evaporate. As a result, your body has to work harder to perform a given activity than it would in non-humid conditions.

So if running in humidity “feels harder, it’s because it is,” Kaila DeRienzo, certified personal trainer and certified run coach in South Carolina, tells Runner’s World. To get more specific, during humid runs, your heart rate will likely climb, your core temperature will be elevated, and “your overall effort and exertion is going to increase,” says Lui. “Sometimes,” she adds, “we might even feel a little bit lethargic as well.”

Strava data backs this up. According to metrics shared with Runner’s World, run pace slows as humidity climbs. In 80 degrees Fahrenheit and 30 percent humidity, for example, the average run pace for Strava users is 9:19 per mile. At that same temperature with 70 percent humidity, the average decreases to 10:14 per mile. And at 90 percent humidity and higher, it drops to an average pace of 11:07 per mile.

When scoping your weather app for humidity data, keep in mind that humidity percentages are relative to the temperature outside, Kai Ng, USATF- and RRCA-certified run coach in New Jersey and New York, tells Runner’s World. That means 50 percent humidity is going to feel a lot different on a 60-degree day versus a 90-degree day.

For a more straightforward metric that involves zero math calculations, check out the dew point reading, which in the Apple Weather app is listed alongside humidity metrics. A dew point of under 60 degrees indicates non-humid conditions, a dew point of around 65 to 70 can start to feel uncomfortable, and a dew point over 75 is “miserable,” says Ng.

Running in high humidity is never going to feel amazing but there are steps you can take to make it more tolerable. Here’s what the experts recommend.

Because humidity can cause your body to work harder to perform a given activity, it’s a smart idea to dial back the intensity of your runs so you don’t overexert yourself and thus up your chances of heat-related illnesses. Some ways to do so: Run by effort level instead of trying to hold a specific pace, do an interval workout instead of running continuously, or go for total time instead of distance.

For example, instead of tackling five miles at marathon pace, ditch your watch and run five miles at marathon effort. Or, in lieu of a four-mile tempo run, do four mile repeats with ample recovery in between, suggests Ng. Another idea: Instead of striving for 10 miles, run for 90 minutes and stop after that point, no matter what the distance on your watch says.

If you’re really itching to run a certain pace, simply insert walk breaks into your workout to make that more doable, says DeRienzo. This could look like running for five minutes at a specific speed, then walking for a minute and repeating several times.

Point is, you can still run outside in the humidity, you just need to be smart about adjusting your workout accordingly, and there are lots of easy ways to do so.

Think of your body as a house and your skin as the chimney. “You never want to cover the chimney when heat and steam is trying to escape your house,” says Ng. On a hot, humid run, steer clear of clothes that cover up all your pores, which prevent your sweat from evaporating. “The less clothing, the better,” says DeRienzo.

This could mean running in just a sports bra and shorts for women or just shorts for men. Of course, do what makes you comfortable, but if you err on the side of scantily clad, know that “nobody’s judging you,” says DeRienzo, and “you are making the best decision for you.” (Just make sure to wear sunscreen to avoid skin damage, she adds.)

Also important: Pick loose, flow-y garments over form-fitting attire—“you want to allow as much air [as possible] to touch your skin,” says Ng—and opt for clothing made with sweat-wicking materials over cotton, as the latter holds onto moisture instead of allowing it to evaporate.

The color of your garb matters too, as darker hues absorb more of the sun’s rays than lighter colors, says DeRienzo. So leave that black or navy blue kit at home and wear your white or other light-colored gear instead.

Lastly, consider a visor over a traditional hat, as the former provides more ventilation for your head while still shielding your face from harsh rays, says DeRienzo. Plus, visors are trendy right now, says DeRienzo, so you can look stylish while staying cool.

On especially humid days, your best bet might be moving your run inside to a treadmill or indoor track. True, indoor workouts can feel like a slog, but when the weather’s bad enough that it would really hamper your performance (and put you at risk for heat-related illnesses), indoor sessions allow you to still get in a quality workout while minimizing health risks.

Everyone responds to humidity a little differently, but as a general rule of thumb, opt for an indoor session whenever the dew point is 70 degrees or higher, advises Ng.

Fun fact: It can take about two weeks for your body to physiologically adapt to exercising in a hot climate, according to research. So while your first hot, humid run of the season might feel especially awful, give it some time and your body will improve its tolerance.

That said, there are some things you can do outside of your runs to aid in this adaptation process, like going for walks in the humidity or regularly visiting the steam room to get your body used to humid conditions, says Ng. “Don’t be like ‘Oh, man, it’s so humid outside, I’m just gonna stay inside until I run’,” says Ng. With that mentality, “it’s going to take you even longer for your body to adapt.”

Taking a cold shower before you lace up can help lower your body temperature and thus allow you to start your workout at a lower temp, Ng explains. This will then reduce your chances of overheating in hot, humid conditions. So the next time you’re eyeing an outdoor run but the dew point seems questionable, strip down first for a chilly rinse.

Because it’s harder for your body to cool itself during humid runs, bring along ice to help aid the process. One idea: Fill an insulated bottle (like a HydroFlask) with ice and place it alongside your other fluids in a hydration pack with bottle holders, says Ng. Then, throughout your run, retrieve ice cubes and place them under your hat or in your clothing for instant cooling.

You can also drop ice in a bag and store that under your hat or the back of your sports bra, says DeRienzo. Another option: Carry slender ice packs in your hands—DeRienzo recommends reusable ones by Tourit or soft gel packs from Icewraps.

Another cooling option: sponges. During the 2021 Chicago Marathon, which was unusually hot and humid, race organizers passed out sponges to participants, who then soaked them in water along the way and used it as a cooling tool, says DeRienzo, who finished the race with a sponge in her hand. She describes sponges as a “cheap and effective” way to cool yourself on a humid run. Simply store the sponge in your shorts or sports bra; wet it whenever you pass a water fountain, bathroom sink, or other potable water; and squeeze it over your head and arms for sweet, sweet relief.

Two common mistakes Lui sees athletes make in humid conditions include not carrying any fluids on a run, and sipping only plain water. The first is a no-no since research shows that as little as 2 percent dehydration can hamper performance. Indeed, mild dehydration can lead to increased effort, decreased output, and impaired cognition, according to Lui.

But it’s not enough to simply pack a bottle of plain H2O. “A lot of people might think this is adequate to replenish fluids, but it’s actually not going to hydrate us as well,” says Lui. In severe cases, drinking a lot of plain water and sweating heavily can lead to a condition called hyponatremia, which occurs when there’s too much water and too little sodium in your body, Lui explains.

To avoid this, hydrate midrun with an electrolyte drink—like Nuun, Scratch Labs, or Gatorade—which will help replace electrolytes lost through sweat, including sodium, potassium, magnesium, and calcium. The general rule of thumb is to hydrate with electrolytes during any run lasting an hour or longer, says Lui, but that threshold may be lower in especially hot, humid conditions and depending on your own tolerance for warm weather.

On shorter runs, “there really is no harm in carrying fluids, especially if you’re training for something like a marathon because it can train you to get used to what it feels like running with a handheld bottle and carrying your fuel,” Lui explains.

Aim to imbibe 16 to 20 ounces of electrolyte drink per hour of exercise, and ensure that includes at least 500 to 600 milligrams of sodium per hour. Salty sweaters may need more–up to 1,000 plus milligrams of sodium per hour, says Lui.

Hydration doesn’t just matter during your runs—it’s important to be well-hydrated in general if you want to function and feel your best. When exercising in humid conditions, increase your fluid and electrolyte intake before, during, and after a run, advises Lui. “I know it seems like a lot, but we’re not only training for one specific training run, it’s also preparing for the rest of the day so that we don’t get dehydrated and feel fatigued and have to deal with headaches all day,” she says.

Part of this involves going into a run well-hydrated, which you can do by consuming an electrolyte drink about 30 to 60 minutes before you lace up, says Lui. This type of prerun hydrating is generally recommended for longer and/or higher intensity runs, but feel free to also try it on a shorter run, especially if you’re not planning to tote fluids with you, says Lui.

You may also consider sipping an electrolyte drink and increase overall fluid intake the day or night prior to a long run “just to give your body some time to really absorb it and digest everything,” says Lui.

Before longer and higher intensity humid runs, consider eating a salty, carb-rich snack to provide quick energy, as well as a dose of sodium for your workout, suggests Lui. This could look like chowing a handful of pretzels or goldfish 15 to 30 minutes before you run, or eating a slice of toast with banana and salted peanut butter about an hour prior.

Also, don’t be afraid to drink and eat some saltier beverages and food throughout the day, especially if you have a longer run on your weekly schedule, Lui says. While those who are sedentary or casual exercisers—as well as those with a medical diagnosis or family history of high blood pressure or kidney diseases—might need to watch their sodium intake, runners who sweat a lot through the miles need more than the average population.

It’s not uncommon (or ill-advised) for runners to have at least one electrolyte-containing product per day, if not more, depending on the product concentration, Lui adds. (If you think you may fall into the category of needing to monitor sodium intake, check with your doctor.)

Hands down the most important thing you can do when running in humidity is listen to your body. Heat-related illness can be super dangerous, so it’s important to know the signs and symptoms.

For heat exhaustion, these symptoms include heavy sweating, tunnel vision, dizziness, rapid pulse, fatigue, headaches, muscle cramps, nausea, feeling like you’re going to faint, and getting goosebumps in hot weather, according to the Mayo Clinic. If you suspect you have heat exhaustion, stop exercising immediately, get to a cooler place, and drink fluids.

To that end, run with a friend or group in hot, humid conditions, says Ng. There’s always safety in numbers.

Jenny is a Boulder, Colorado-based health and fitness journalist. She’s been freelancing for Runner’s World since 2015 and especially loves to write human interest profiles, in-depth service pieces and stories that explore the intersection of exercise and mental health. Her work has also been published by SELF, Men’s Journal, and Condé Nast Traveler, among other outlets. When she’s not running or writing, Jenny enjoys coaching youth swimming, rereading Harry Potter, and buying too many houseplants.

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