According to a new study of Olympic athletes, about 25 percent of swimmers had verified asthma. What is odd is that it is more common in athletes from some parts of the world than others which would seem to eliminate intensity of swimmer training, or long hours spent in the water, which may expose swimmers to more chlorine byproducts - unless Olympic swimmers in some parts of the world do not train as hard.
It could be that people with asthma self-select swimming. It could be that some have a doctor's note so they can use inhalers that are otherwise banned.
It isn't just swimming where asthma rates are higher. In non-endurance events like fencing, volleyball and table tennis, asthma rates are lower than in endurance competitions like triathlon, pentathlon or cycling.
Asthma very common among Olympic-level swimmers By Kathryn Doyle, Reuters
