Heavy training in cold, dry or polluted environments can lead to irritation of the airways. Many athletes, runners, swimmers eventually develop a form of Asthma called EIA.
This can be tested for with an EVH (Eucapnic Voluntary Hyperpnoea) test, or an Exercise test.
It is treated with standard Asthma medication such as steroid inhalers and beta 2 agonists (Salbutamol).