Allergic to Exercise?

Ever heard someone say they are allergic to exercise? For most people, the comment would be seen as a joke, but it is actually a real and serious condition!

Imperial College News reported a patient who experienced anaphylaxis after eating his Christmas dinner and then going for a walk. His face and body swelled up, his skin became covered in hives and he had difficulty breathing. He just made it back home before collapsing, losing consciousness twice before an ambulance rushed him to the hospital. Following extensive tests he was diagnosed with wheat-dependant exercise-induced anaphylaxis, in other words, anaphylactic shock caused by doing physical activity but only after eating wheat.

There are 2 types of triggers for Exercise-Induced Anaphylaxis:

1. 'Exercise-Induced Anaphylaxis (EIA)

2. Food-Dependent, Exercise-Induced Anaphylaxis (FDEIA).

The 1st happens without food and 2nd when exercise is combined with food.


Symptoms of EIA can start at any time during exercise. In 90% of patients, the symptoms tend to start after 30 mins. For some people, the allergic reaction can be mild such as itchy red hives but in a fully developed EIA reaction, patients can develop a whole range of symptoms including itchy hives, stomach cramps, nausea, vomiting, difficulty breathing, a feeling of choking, a frontal headache and excessive tiredness. Cardiovascular symptoms, including collapse or unconsciousness, are reported in one-third of EIA patients and severe symptoms can happen as late as 72 hours after the initial ones.

In patients with FDEIA, where the ingestion of a food together with physical exercise triggers anaphylaxis, the food culprit may have been eaten before or after the exercise, a few minutes or even up to several hours! You might not experience any allergic symptoms when you eat the food normally, but it's something about the combination of physical exercise and the ingestion of a particular food(s) that sets off your immune system.

For some, it might not be as simple as avoiding the food triggers though, as there is also a nonspecific form of FDEIA, where eating any food before exercise can trigger a reaction. There's also a chance it could be something you're breathing in, such as dust mite debris, or mould spores. The medical recommendation is to stop eating 6 to 8 hours before exercising, and don't exercise in very hot or cold weather. Fatalities or near-fatalities are thankfully very rare.

Ever heard of this?

Sources: Imperial.nhs.uk; National Library of Medicine - Exercise-Induced Anaphylaxis