Exercise and airway physiology: interactions with immune and allergic responses

In this chapter, the relationships between exercise and lung function are analysed. The presence of airflow obstruction may impede an efficient ventilatory response to exercise because of the occurrence of dynamic hyperinflation. In normal subjects, bronchodilation may occur during exercise and this may also be true in asthmatics that are bronchoconstricted at rest. However, in a number of asthmatics with normal lung function at rest, bronchoconstriction may occur after a short submaximal exercise or even during it if the bout is prolonged. The mechanisms by which exercise-induced bronchoconstriction develop are triggered by thermodynamic events and involve inflammatory cells present in the airways at the time of exercise. Furthermore, recent data suggest that exercise may prime airway inflammation, thus leading to airway hyperresponsiveness in elite athletes.