There are a lot of obstacles that come with winter running: freezing temps that sap motivation, slick weather that renders the roads unsafe, bulky gear that slows you down. But one of the worst is that fiery sensation of cold air searing your throat, which makes catching your breath in already-tough conditions even harder to bear. If you’ve ever come home from a run in the cold wondering why you suddenly feel like you’ve come down with a case of strep, here’s what’s going on.

How does cold air affect your throat?

Cold air is typically dry, and when your throat gets dry, it feels painful. “The respiratory system begins in the nose, and the role of the nose is to warm, filter, and moisturize the incoming air, which facilitates the travel of oxygen into the deepest part of the lungs,” explains Gustavo Ferrer, M.D., founder of the Cleveland Clinic Florida Cough Clinic. Bypassing the nose skips this process if you’re breathing through your mouth.

That matters because “the cold, dry air hits the mucosal lining, wicking away valuable moisture,” explains Naresh Rao, an osteopathic primary care physician and sports medicine specialist at Sports Medicine Chelsea in New York. “And that drying effect on the mucosa breaks down the barrier of protection for the cells that line the respiratory tract, which triggers a pain response in the nerves that alerts you to prevent further damage.”

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Inside your nasal passages are tiny blood vessels that warm the nose and small cells called cilia, which trap airborne particles such as dust and fumes. Breathing through your mouth prevents the cold air from being warmed up, which dries out through tissue, explains Ferrer. Also, your throat isn’t designed for trapping pollutants that can cause all kinds of illnesses. “The cold air plus the particles can cause severe irritation, sore throat, and increase secretions followed by a runny nose, making your breathing difficult—a common phenomenon in runners,” he says.

Your respiratory system requires humidity around 40 percent for proper functioning and protection, says Rao—but that’s not to say you shouldn’t be running if conditions are drier than that. It’s fine in the short term (spring marathon training stops for no weather!), but if left unchecked, that drying effect can actually start to damage your cells—symptoms include runny nose, sore throat, difficulty swallowing, hoarse voice, and, in more severe cases, difficulty breathing, all of which can affect running negatively and lead to decreased performance, Rao adds. And “long-distance runners can run the risk of developing severe throat irritation that facilitates the penetration of viruses, bacteria, and environmental toxins,” warns Ferrer.

What can you do about it?

You can’t control the weather, but you can control how you prep and dress your body for it. First, “train yourself to close your mouth and breath through the nose” to warm up and humidify the air that goes into your body, says Ferrer. That’s easier said than done on the run, though, so cut yourself some slack as you acclimatize to the conditions you’re trying to run in—you may have to run at a slower pace and for a shorter duration, then slowly build up so your body can adapt.

Wearing something that protects your face can also help warm up the cold air you’re breathing. But “avoid using a full ski mask—it can get wet, block your vision, and overheat the inhaled air, which actually makes your breathing more difficult,” says Ferrer. Instead, loosely cover your mouth and nose with a breathable gaiter, which will help warm up and add moisture to the water you breath in,” says Rao.

Cold-Weather Running Gear
Best Hat
Merino Sport 250 Beanie
Smartwool Merino Sport 250 Beanie
$30 at Amazon

Made of 100 percent merino wool, this beanie is perfect for all wintry weather thanks to a double-locked construction.

Best Base Layer
Nike Dri-FIT Miler Men's Long-Sleeve Running Top
Nike Nike Dri-FIT Miler Men's Long-Sleeve Running Top

Nike’s dri-fit technology is designed to be ultralight and sweat-wicking while keeping you covered.

Best Tights
Women's ColdGear® Authentics Leggings
UnderArmour Women's ColdGear® Authentics Leggings

Under Armour's ColdGear® leggings are designed to combat chilly weather.

Best Jacket
Canopy Jacket

The lightweight, breathable fabric packs a punch against inclement weather. Shop women's here.

Finally, stay hydrated! It’s easier to forget about proper hydration in the cold because you’re aren’t sweating like crazy, but dry air actually causes water loss, which can lead to dehydration. Without humidity, you’re not breathing in any water—so “the more you breathe, the more water you lose,” says Rao.

Headshot of Ashley Mateo
Ashley Mateo
Ashley Mateo is a writer, editor, and UESCA- and RRCA-certified running coach who has contributed to Runner’s World, Bicycling, Women's Health, Health, Shape, Self, and more. She’ll go anywhere in the world once—even if it’s just for a good story. Also into: good pizza, good beer, and good photos.