In fact better treatment with medicines can have a powerful effect on exercise-induced asthma. The better your asthma control, the less you will be troubled by exercise-induced asthma. Exercise-induced asthma is an excellent example of a problem which you can begin to solve once you understand it better. The last time I read this up, the evidence was that increased breathing during exercise causes cooling and drying of the lining of the air passages and that these are necessary for someone to get exercise-induced asthma. This explains why warm moist air protects against exercise-induced asthma.
Nobody knows exactly why the drying and cooling of the airway linings causes the asthma episode.
Well, of course you would rather not have asthma of any kind, however 'useful'. But seriously, exercise-induced asthma can be useful for diagnosing asthma in a child. Exercising a child for about 6 minutes is a convenient and safe way of provoking a mild asthma attack, and this has led to many children getting early and appropriate advice and treatment. We can exploit this feature of asthma to help defeat asthma. Exercise-induced asthma has also been useful in asthma research.