Exercise Induced Asthma, or EIA (also known as Exercise-Induced Bronchoconstriction, EIB) is a form of Asthmaplugin-autotooltip__plain plugin-autotooltip_bigAsthma

Asthma is a common, (and currently incurable) long term inflammatory disease of the airways of the lungs, characterized by variable and recurring symptoms such as reversible airflow obstruction, and bronchospasm. Episodes of asthma frequently feature wheezing, coughing, chest tightness, and shortness of breath. (constriction of the airways) which is triggered by strong exercise. It was first reported in 1989.

It's prevalent amongst professional athletes at a far higher level than the general population. For example, some studies have put the prevalence as high as 45% for cyclists and 55% for skiers and skaters,

Although the trigger is known (heavy exercise) the biological mechanisms which lead to EIA asthma attacks, and to such a high prevalence in athletes, are currently unknown.

It's suggested that extensive breathing of cold air via the mouth may be a factor - although it's also found (though to a lesser extent) in athletes who compete in 'Summer' sports.

For extensive technical details see Allergy Journal Volume 63, Issue 4.