Contribution of β-adrenergic receptors to exercise-induced bronchodilatation in healthy humans

► Exercise is a potent natural bronchodilator agent in healthy humans. ► Reduction of vagal tone has been suggested to be one of the major mechanisms. ► In our study bronchodilatation increased as a function of exercise hyperventilation. ► This was partially blunted by carvedilol, a β1-β2-adrenergic receptor blocker. ► Our findings suggest that β2-adrenergic receptors and airway stretching contribute to reduce bronchial tone with exercise.