RT Journal Article SR Electronic T1 The breathless adolescent asthmatic athlete JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 713 OP 720 DO 10.1183/09031936.00068510 VO 38 IS 3 A1 K-H. Carlsen YR 2011 UL http://erj.ersjournals.com/content/38/3/713.abstract AB This article concerns physical activity and sports in asthmatic adolescents. Exercise-induced asthma (EIA) is found in 8–10% of the normal child population and in ∼35% of children with current asthma, as reported in a population-based birth cohort study. The mechanisms of EIA are related to markedly increased ventilation during exercise, which causes increased heat and water loss through respiration, leading to bronchial constriction. In athletes and especially in endurance athletes, the repeated daily physical activity during training will, over time, cause epithelial damage and increase inflammation in the respiratory mucosa. With increased exposure to environmental agents, such as as cold air in skiers and chlorine compounds in swimmers, the athlete may contract symptoms and signs of asthma and bronchial hyperresponsiveness, either worsening existing asthma or causing symptoms in a previous healthy adolescent athlete. There are several causes of breathlessness in adolescents, including EIA, vocal cord dysfunction, poor physical fitness and others, which are important to consider in the diagnostic procedure. The asthmatic athlete should follow the same guidelines for treating their asthma as an ordinary asthmatic patient, with careful consideration of the special diagnostic rules given for the use of asthma drugs in sports, especially for inhaled β2-agonists.