Allergic to Running?

Earlier this week I posted on facebook, asking if any of my friends wanted to join me in an Iron Girl Triathlon this fall, So far, there has been a distinct lack of takers. Or to be more precise, nobody, not one single solitary person, has taken me up on the challenge.

I did, however, hear a lot of reasons why people didn’t want to swim, bike and run with me at 7am on a September morning.  Among the best of these: “I’d love to, but I think I’m allergic to sport.”

I think she was trying to be funny – though with my friends you never can tell!

You see, not only do most of my friends have a wicked sense of humor, most are also involved one way or another with healthcare, and maybe, just maybe, she who will remain nameless, really is allergic to running.

While it may sound like the perfect excuse, people can in fact suffer an anaphylactic reaction to exercise.  But, before you cancel your gym membership and start justifying your life as a couch potato, I should point out that it’s generally pretty rare.

People usually associate working out with an increased heart rate and a nice endorphin rush — not hives, or shock. But it can happen.

Cholinergic urticaria, a common type of heat rash, can occur when there’s an increase in body temperature and when mast cells in the skin break down right before releasing sweat. Studies suggest up to 11% of adults experience post-exercise hive attacks, men, more commonly than women.

Even worse is exercise-induced anaphylaxis.  Like the name suggests, it’s triggered by exercise, especially running. Anaphylaxis, is more commonly seen after insect stings or eating shellfish and peanuts.  And just as with food allergies, those affected by exercise can experience symptoms including vomiting, hives, difficulty breathing, collapse and even death…although fewer than 1,000 cases and only one exercise-related fatality have been reported since the 1970s.

So while running (or Iron Girl Triathlons) may not be everyone’s favorite fitness activity, the “I’m allergic” excuse is reserved for those (un)lucky few.

And even then, most cases can be avoided.

Usually, it’s triggered by eating certain foods before exercise. But this isn’t just your average food allergy says allergist Jacqueline Eghrari-Sabet MD – a spokeswoman for the American Academy of Allergy, Asthma and Immunology.  “Eating shellfish and sitting there? Nothing. But eating shellfish and exercising? For these people, it’s bad news.”

As you exercise and your heart rate speeds up, your blood starts whizzing through organs much faster than it normally does. With every trip your blood takes to your stomach, it’s picking up more, of say, the peanuts. For those with exercise-induced anaphylaxis, the normal amount of peanut antigens picked up by the blood isn’t enough to bother them. But while exercising, the extra peanuts their blood is picking up causes an allergic reaction.

So next time you are convinced that if you spend even one more minute on the treadmill, you will die? Maybe it’s not all in your head.