Background: Asthma prevalence in athletes is variable, depending on the sport and training conditions.
Aims: To investigate the prevalence of obstructive airflow limitation, asthma control and lung volume differences in a control group and five groups of collegiate athletes--outdoor field, indoor court, endurance, combat sports and swimming.
Methods: Three hundred and five athletes completed a respiratory questionnaire and performed spirometry during normal training conditions, to determine FEV1, FVC and PEFR pre- and at 5, 10 and 15 minutes post-exercise. Between and within group analysis was carried out using single factor and repeated measures ANOVA.
Results: Previous diagnosis of asthma was reported by 24%, outdoor field sports 4.9%, indoor court sports 2.3%, endurance events 2.6%, combat sports 3%, swimming 6.9% and controls 4.3%. Mean FEV1 and FVC data, expressed as percentage of predicted, were greatest in swimming and lowest in controls. Swimming showed a significant rise in FEV1 post-exercise, indoor court and endurance sports demonstrated no change and outdoor field, combat and control groups showed a fall in FEV1 post-exercise.
Conclusion: Warm humid training conditions appear protective against exercise-induced asthma. The greatest reductions in lung volumes occurred following high intensity exercise under cool conditions in the poorly aerobically conditioned.