Asthma, airway inflammation and epithelial damage in elite athletes.

I n recent years there has been special focus on the increased occurrence of asthma and bronchial responsiveness among top athletes within endurance sports. As early as 1989, an increase in nonspecific bronchial responsiveness after heavy endurance training was found in young competitive swimmers [1]. Later, reports were made concerning increased prevalence of asthma and bronchial hyperresponsiveness to metacholine among top cross-country skiers [2, 3]. Reports came from Trondheim (Norway) regarding inflammatory changes in bronchial biopsies appearing during a winter season in young competitive cross-country skiers [4, 5]. These studies confirmed that both bronchial responsiveness and airway inflammation increased through heavy endurance training [1–5].