“The nasal passages have a normal physiologic response to different levels of activity,” says Michael Yong, MD, board-certified otolaryngologist and fellowship-trained neurorhinologist at Pacific Neuroscience Institute in Santa Monica, California.

Aerobic activities such as cycling, running, and hiking tend to create more of a response, but any exercise can have an effect, Dr. Yong continues. When your heart rate increases, the lining of your nasal cavity tightens up so more air is able to travel into your nose. When this happens, the mucus produced in the nose becomes thinner and runnier than normal.

“This can result in some dripping in the front of the nose or at the back of the throat,” Yong says.

Still, some people may be more prone to a runny nose during exercise (aka exercise-induced rhinitis) than others. Some people even experience sneezing, itching, and congestion.

Ahead, experts break down the potential reasons your workouts give you the sniffles and how to prevent them.

1. You have allergic rhinitis

With more air flowing into the nasal passages during exercise, there’s a greater risk of irritants finding their way in—especially if you have allergic rhinitis (nasal allergies).

Allergic rhinitis is also commonly known as hay fever. It occurs when your immune system overreacts to something in the environment, such as pollen or mold, causing runny or stuffy nose, sneezing, and itchy eyes, mouth, or skin, according to the American College of Allergy, Asthma, and Immunology.

Combine an allergen with the normal effects of exercise on the nasal passages, and you’ve got a surefire recipe for a runny nose disaster.

To lower your odds of a runny nose, choose your workout location carefully. For example, avoid exercising outdoors on high pollen days if you’re allergic to pollen, says Tiffany Owens, MD, allergist and immunologist at The Ohio State University Wexner Medical Center.

A daily nasal spray with antihistamines and/or corticosteroids may also help by lowering inflammation of the nasal lining. “Some patients with allergic irritation inside the nose find that this helps it be less reactive during any time, but especially when exercising,” Yong says.

You can get prescription and over-the-counter nasal sprays using different medication types. Chat with your doctor to find the best option for you.

It’s perfectly normal for your nose to get runny during a workout.

2. You have nonallergic rhinitis

If your nose gets stuffy or drippy during exercise but you don’t have itchiness (or illness), you may have nonallergic rhinitis.

Unlike allergic rhinitis, nonallergic rhinitis has no clear cause, per the Mayo Clinic. However, Yong describes it as an issue of nerve sensitivity inside the nose. Basically, the nerves inside your nasal passages are over-sensitive to certain triggers, which could include weather changes, medications, smells, hot or spicy foods, and irritants like dust or fumes. When exposed to these triggers, your nose reacts by creating more mucus.

Similar to its allergic cousin, nonallergic rhinitis can make your nose run during exercise if you encounter triggers. Think: Walking outside during the winter when it’s a bit colder out, doing yoga in a heated room, or inhaling greater amounts of fumes from passing cars while running.

Avoiding your triggers is the best way to prevent a runny nose during exercise. However, because this isn’t realistic for many of us, it’s worth talking to your doctor about other options, including medication.

“We often prescribe an anticholinergic spray called Atrovent, which acts to really dampen the nerve sensitivity and reactivity inside the nose, which can help to reduce the stimulation of the mucus glands and ultimately reduce the amount of mucus produced during those periods of activity,” Yong says.

The anticholinergic spray is typically used on an as-needed basis, so if you often have reactions from exercise, you could take it before your workout, Yong adds.

3. You have a deviated septum

Owens notes that there could be a structural reason for your runny nose during exercise: A deviated septum.

If you have a deviated septum, the thin wall of bone and cartilage that divides the inside of the nose in half (the nasal septum) is displaced to one side. This makes one nasal passage smaller than the other.

It’s estimated that as many as 80 percent of people have a deviated septum, per the American Academy of Otolaryngology-Head and Neck Surgery. Some of us were born with it, while others got it from trauma or injury to the nose.

For many, their deviated septum causes no issue. However, for others, their deviated septum is severe enough to block one side of the nose and create congestion. You may find this congestion causes your nose to run during a workout sesh.

If that’s the case, your doctor can recommend medications that can manage your symptoms. These may include decongestants (best used short-term) to reduce nasal tissue swelling, antihistamines to prevent allergy symptoms such as a stuffy or runny nose, and nasal steroid sprays to reduce nasal swelling, per the Mayo Clinic.

Who’s most likely to get a runny nose during exercise?

It’s perfectly normal for your nose to get runny during a workout. However, people with allergic rhinitis, nonallergic rhinitis, and/or a significantly deviated septum are more likely to experience nasal drippage.

Even within those groups, certain people may be more affected than others. “For nonallergic rhinitis, we tend to see, anecdotally, as people get older, sometimes that can have an effect on the nerves inside the nose, which can end up in people having more mucus production,” Yong says.

Yong adds that people with sinus infections may have a higher likelihood of a runny nose during everyday life and exercise.