Exercise-induced bronchoconstriction: burden and prevalence.

Exercise-induced bronchoconstriction (EIB) is common in asthma patients as well as athletes. This article provides an overview of the prevalence and impact on quality of life (QoL) of EIB based on an analysis review of selected literature. The term EIB is preferred to exercise-induced asthma because EIB does not cause asthma, and asthma is not a prerequisite to have EIB. EIB is extremely common in asthma patients and is reported in most asthma patients. Several factors may increase the prevalence of EIB including severity of asthma, family history of asthma, atopy, respiratory infections, and urbanization. Some studies also suggest EIB is more common in girls than boys and in younger-age children. EIB also occurs in athletes, even without asthma. The prevalence of EIB varies among sports with some of the highest rates observed in Nordic combined, cross-country, and short track Winter Olympic athletes. Environmental factors may have a role in EIB including chlorine in swimmers and particulate matter exposure from fossil-fueled ice resurfacing machines in ice arena athletes. Accumulating evidence indicates that the burden of EIB impairs QoL. EIB is a common condition in asthma patients and athletes and adversely affects the QoL and the ability to participate in sports.