Seasonal and environmental allergies affect millions, often causing symptoms that interfere with daily life, including physical activity. The effect of physical activity on the body’s allergic response is nuanced, depending on the intensity of the workout, the environment, and the individual’s condition. Exercise can offer immediate temporary relief, but it can also trigger a flare-up if not managed properly. Consistent, long-term exercise, however, offers measurable changes to the immune system that help manage chronic allergic reactivity.
The Immediate Effects on Allergic Symptoms
During a workout, the body releases a surge of catecholamines, including epinephrine, which acts as a natural decongestant and bronchodilator. This physiological response temporarily shrinks swollen nasal passages and opens up airways, reducing allergy symptoms like congestion or a runny nose. Studies on individuals with allergic rhinitis show that moderate-intensity exercise can decrease symptom scores immediately following the activity. This acute effect can make a workout feel like a break from seasonal discomfort.
However, the rapid breathing that accompanies strenuous activity, especially when performed outdoors, can introduce a large volume of allergens directly into the airways. For individuals with asthma or heightened airway sensitivity, this can trigger Exercise-Induced Bronchoconstriction (EIB). EIB causes the air tubes to narrow during or shortly after exercise, leading to symptoms such as wheezing, coughing, and chest tightness. This risk is compounded by environmental factors like cold, dry air or high levels of pollen and air pollution.
Intense physical exertion also affects mast cells, which are the cells responsible for releasing histamine and other inflammatory mediators in an allergic reaction. Vigorous exercise can lower the threshold at which these mast cells degranulate, particularly when combined with factors like a specific food or medication. This phenomenon is implicated in rare but severe reactions like exercise-induced anaphylaxis (EIA). EIA occurs when physical activity alone or combined with a food allergen provokes a systemic allergic response, with symptoms ranging from generalized itching and hives to respiratory and cardiovascular issues.
Systemic Benefits: Reducing Chronic Inflammation
Beyond the immediate effects, consistent physical activity provides a long-term benefit by reshaping the body’s immune response to allergens. Allergies are characterized by a hyper-responsive immune state involving T helper 2 (Th2) cells, which promote the release of antibodies that drive the allergic cascade. Regular exercise helps modulate the immune system by shifting this balance toward a more balanced Th1/Th2 profile. This adjustment dampens the overall pro-allergic response over time.
Skeletal muscle contractions during exercise stimulate the release of signaling proteins called myokines into the bloodstream. These myokines, which include interleukins such as IL-6 and IL-10, play a role in mediating anti-inflammatory effects throughout the body. This chronic increase in anti-inflammatory signaling lowers the baseline level of systemic inflammation, making the body less reactive to common environmental triggers.
Sustained exercise training decreases the circulating levels of pro-inflammatory markers that contribute to chronic inflammation. By maintaining a lower inflammatory state, the immune system becomes less easily provoked by inhaled allergens like pollen or dust mites. This long-term biological change means that while a single workout might offer temporary relief, a consistent exercise regimen can improve the body’s ability to manage allergic disease.
Practical Guidelines for Exercising with Allergies
Managing the risks of exercise-induced symptoms requires a strategic approach, starting with monitoring environmental conditions. Pollen counts peak between the mid-morning and early afternoon, so scheduling outdoor activity for the late afternoon or early evening can minimize exposure. Working out immediately after a rain shower is also beneficial, as the moisture helps to wash pollen out of the air.
On days with high pollen counts, poor air quality, or significant wind, switching to an indoor workout is a safer alternative. For those with EIB, a proper warm-up lasting 10 to 15 minutes is advised, as this helps the airways adjust gradually to the increased airflow. Hydration is also important, as moist airways are less prone to irritation from allergens or dry air.
When exercising outside, consider wearing wraparound sunglasses and a hat to create physical barriers that prevent allergens from reaching the eyes and hair. Immediately after returning indoors, shower and change clothes to remove any collected pollen or mold spores. Individuals who experience persistent or severe symptoms should consult a healthcare provider to discuss pre-exercise treatments, such as taking an antihistamine or using a prescription inhaler before their workout.