Not a Joke: Some People Really Are Allergic to Exercise

Ben-Gurion in a gym / Official Facebook of Benjamin Netanyahu

People who do not enjoy working out sometimes jokingly say they are “allergic to sports.” But in rare cases, this is a real medical condition that can be very dangerous. The condition is called exercise-induced anaphylaxis, or EIA, and it causes a severe allergic reaction during or after physical exertion. It is estimated that between 2.3% and 5% of all anaphylaxis cases worldwide are linked to exercise.

Man scratching his arm / ShutterStock

What does it look like? The symptoms are similar to those of a regular allergic reaction, but they can worsen quickly: severe itching all over the body, rash and redness of the skin, swelling of the lips or face, tingling in the mouth, nausea and vomiting, difficulty breathing, and a drop in blood pressure. In severe cases, there is an immediate risk to life.

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How the phenomenon was discovered The first documented case occurred in the 1970s in the United States, when a long-distance runner was hospitalized several times after suffering severe allergic reactions while running. After a series of tests, doctors discovered that the symptoms appeared only when he exercised after eating seafood. When he ran without eating seafood before exercising, no reaction occurred. Since then, it has become clear that in some cases, the combination of certain food and physical activity is what triggers the allergic reaction.

Foods that can trigger the reaction The most common type is called food-dependent exercise-induced anaphylaxis. Known triggers include:

Seafood Nuts Eggs Milk and dairy products Wheat

However, food is not always the cause. Researchers have found that other factors can also trigger the reaction when combined with physical exertion:

Certain medications Infections and illnesses Hormonal changes Alcohol consumption Pollen and environmental factors

In some cases, exercise alone is enough to trigger an attack.

Woman stretching her wrist / ShutterStock

Which types of activity are more dangerous? According to the data, most cases are linked to aerobic activity such as:

Running Soccer Dancing Cycling Gardening

The condition can appear at any age, but it is most often diagnosed at a young age and in early adulthood.

What actually happens in the body? Despite decades of research, the exact cause is still not fully clear. The main suspect is immune system cells called mast cells. These cells release histamine and other substances that are supposed to protect the body from infections and injuries. In people who suffer from the condition, these cells are activated at the wrong time and cause a sudden release of large amounts of histamine. The result is airway constriction, a drop in blood pressure, and the development of anaphylaxis.

Studies show that even in people who have already been diagnosed, the reaction does not occur with every workout. Sometimes the same person will eat the same food and exercise without any problem, and at other times suffer a severe reaction. This has led researchers to believe that there are additional, still unknown factors affecting the risk.

How is it treated? The main goal is to reduce the risk of attacks and their severity. Recommendations include:

Identifying personal triggers and avoiding them Starting physical activity gradually Avoiding exercise for at least four hours after exposure to a known trigger Carrying an epinephrine injector, such as an EpiPen, at all times Working out with a partner who knows how to recognize symptoms and call for help Stopping activity immediately when the first signs appear

In some cases, doctors may also recommend treatment with antihistamines.

The good news: although this is a potentially dangerous condition, most people diagnosed with exercise-induced anaphylaxis are able to maintain a fully active and normal lifestyle. The key is awareness, early recognition of symptoms, and following medical instructions. That way, it is possible to keep enjoying the benefits of physical activity without turning a routine workout into a medical emergency.