It has been known for over a hundred years that exercise can induce a runny nose. Between 25% and 50% of athletes will describe experiencing a runny nose during exercise (also referred to as “exercise-induced rhinitis”). While nasal drainage increases, nasal congestion/blockage typically decreases. In fact, studies have shown that during exercise, the resistance of the nasal passages can decrease (i.e. the nasal passages become more open) so that more air can pass through. The characteristic increase in nasal drainage is seen in all manner of sports from typical land sports (for example, running or biking) to skiing to swimming. The exact mechanisms for exercise-induced rhinitis are unclear but it may depend on the exact circumstance and the sport during which it occurs.
First of all, at least one study has shown that exercise-induced rhinitis occurs more frequently in people with allergies. It is therefore possible that in some individuals, increased airflow through the nose due to the reflex nasal decongestion and increased respiration (breathing faster) that occur during exercise may introduce more allergens into one’s nose and hence trigger a runny nose. Whether these allergens are pollens floating around outdoors or dust in your at-home exercise studio, this could be a reason for the runny nose your experience when you exercise. Second, irritants can also trigger runny nose. For example, an irritant — in the form of chlorine— is thought to be the likely culprit for the runny nose commonly observed in swimmers. However, it is also important to know that anyone who exercises in an urban environment (or even in the suburbs of an urban environment) is constantly being exposed to irritants in the air in the form of particulate matter and pollution. Moreover, allergens are also irritants to the lining of the nose. So even in a person who doesn’t have allergies, inhalation of allergens can still irritate the lining of the nose. As another possible mechanism for exercise-induced rhinitis, cold air can also cause runny nose by activating nerves in the nose to stimulate the lining of the nose to produce mucus (also referred to as “vasomotor rhinitis”). It is this stimulation by cold air that is thought to cause “skier’s nose” and runny nose in close to 50% of athletes who play winter sports.
The question that most people reading this are likely asking is “what can I do about it?” The fact that there may be different mechanisms of action for exercise-induced rhinitis makes it hard to make broad statements about how to treat it or prevent it. However, individuals who know they have allergies may want to consider using allergy medications on a more consistent basis. In fact, there is at least one randomized controlled trial showing that intranasal steroid sprays (an effective, first-line treatment of allergies) may improve exercise-induced reactivity of the airways. Another easy intervention for those who work out at home may to place a portable air purifier in the same room that they exercise in. For those who mostly experience runny nose while playing winter sports, a prescription nasal spray called ipratropium, which directly acts to inhibit nerves in the nose that stimulate mucus production, may be helpful. However, whether to pursue treatment options with your doctor in large part depends on whether exercise-induced rhinitis is a significant burden to you. In most cases, even in high performance athletes, it is not a major impediment to athletic performance, although it can certainly affect quality of life. In many cases, just knowing why these symptoms are occurring may be helpful and put one’s mind at ease. For those who want to do something about, talk to a doctor about it because there are definitely treatment options.