Dry Mouth When Running? Here’s Why and What to Do About It

Dry mouth during sports like running can stop you right in your tracks. Feeling parched or like your mouth is full of cotton is common for many runners, especially when exercising in the heat. Although a medical condition or medication could be to blame, the cause is often related to hydration.

Dry mouth, or xerostomia, is a condition that occurs when your salivary glands don't make enough saliva, according to the Mayo Clinic. When this happens, you may notice dryness or stickiness in your mouth and throat.

Some of the most common reasons for dry mouth are medical conditions and medication side effects, dehydration and evaporation, says Brett G. Toresdahl, MD, assistant attending physician at the Hospital for Special Surgery and research director for the HSS Primary Care Sports Medicine Service in New York City. Stress or anxiety before a race can also cause dry mouth during running, he says. Here's what you need to know about key causes.

"When running or exercising and breathing with your mouth open, evaporation of the moisture in your mouth can lead to dryness," says Kevin W. Farmer, MD, orthopedic sports medicine surgeon at University of Florida Health in Gainesville. This is incredibly common, and most of us don't even think about it, he says.

Mouth dryness can be a sign of systemic dehydration, Dr. Farmer says. In addition to dry mouth during sports or running, other signs of dehydration include:

• Dark urine
• Lack of sweating
• Muscle cramping

That's why it's imperative to hydrate while exercising.

‌Read more:‌ What Really Happens to Your Body When You're Dehydrated

"Some metabolic and autoimmune conditions can lead to persistent dry mouth, as well as certain medications, even without exercising," Dr. Farmer says. If dry mouth persists despite appropriate rehydration and breathing techniques (more on those below), your dry mouth could be a sign of a medical condition or reaction to a medication, and you should follow up with your doctor.

Some of the more common medical conditions related to xerostomia, according to a review in the July-August 2014 issue of ‌Annals of Medical & Health Sciences Research‌, include:

• Diabetes
• Parkinson's disease
• Thyroid disease
• Rheumatoid arthritis
• Viral infections like HIV and hepatitis C

‌Read more:‌ Waking Up With Dry Mouth? Here's What Your Body's Trying to Tell You

If dry mouth is not related to a medical condition or medication, you'll want to try some dry mouth remedies like examining your hydration status and breathing techniques.

Proper hydration depends on the type of training you're doing, Dr. Farmer says. "Before any run, you generally want to drink at least 16 ounces or 2 cups of water approximately 2 hours before you head out for a run," he says. This is also a good time to eat a small snack.

About 15 minutes before your run, he recommends drinking 6 to 8 ounces of water. If you're going to run longer than an hour, make sure you're drinking water at regular intervals during your workout.

Runners who experience dry mouth should first keep track of their fluid intake to ensure that they are properly hydrated throughout the day, Dr. Toresdahl says. Staying hydrated includes any fluids you're getting over the course of a day (including from water-rich foods), as well as in the hours before you hit the pavement.

"While many runners are able to 'drink to thirst,' meaning they can stay adequately hydrated by drinking as needed when they feel thirsty, others may benefit from a consultation with a sports nutritionist or exercise physiologist to get help measuring sweat losses during exercise and create a hydration plan," Dr. Toresdahl says.

In order to avoid evaporation, Dr. Farmer recommends practicing breathing slowly. Take deep breaths and focus on breathing through your nose. "Trying to minimize the amount of mouth breathing you do will decrease the amount of evaporation and dryness," he says.

‌Read more:‌ Staying Hydrated Shouldn't Be Confusing — Here's How to Finally Get It Right