Swimmers show the highest prevalence of asthma among elite athletes, certainly due to chlorine exposure. The consequences of a chronic exposure to chlorine compounds by swimmers and the mechanisms of asthme in this population are still poorly documented. Specific diagnostic criteria have been proposed by the International Olympic Committee - Medical Council (IOC-MC) and World anti-doping agency (WADA) to determine the presence of asthma in athletes. Using the more specific bronchial provocation tests, our aims are