Exercise may increase ventilation up to 200 L/min for short periods of time in speed and power athletes, and for longer periods in endurance athletes, such as long-distance runners and swimmers. Therefore highly trained athletes are repeatedly and strongly exposed to cold air during winter training and to many pollen
allergens in spring and summer. Competitive swimmers inhale and microaspirate large amounts of air that floats above the water surface, which means exposure to
chlorine derivatives from swimming pool
disinfectants. In the summer Olympic Games, 4% to 15% of the athletes showed evidence of
asthma or used
antiasthmatic medication.
Asthma is most commonly found in endurance events, such as cycling, swimming, or long-distance running. The risk of
asthma is especially increased among competitive swimmers, of which 36% to 79% show bronchial hyperresponsiveness to
methacholine or
histamine. The risk of
asthma is closely associated with atopy and its severity among athletes. A few studies have investigated occurrence of
exercise-induced bronchospasm among highly trained athletes. The occurrences of
exercise-induced bronchospasm vary from 3% to 35% and depend on testing environment, type of exercise used, and athlete population tested. Mild eosinophilic airway
inflammation has been shown to affect elite swimmers and cross-country skiers. This eosinophilic
inflammation correlates with clinical parameters (ie, exercise-induced bronchial symptoms and bronchial hyperresponsiveness). Athletes commonly use
antiasthmatic medication to treat their exercise-induced bronchial symptoms. However, controlled studies on their long-term effects on bronchial hyperresponsiveness and airway
inflammation in the athletes are lacking. Follow-up studies on
asthma in athletes are also lacking. What will happen to bronchial hyperresponsiveness and airway
inflammation after discontinuation of competitional career is unclear. In the future, follow-up studies on bronchial responsiveness and airway
inflammation, as well as controlled studies on both short- and long-term effects of
antiasthmatic drugs in the athletes are needed.