Objective: To determine the prevalence of exercise-induced bronchoconstriction among elite long-distance runners in Brazil and whether there is a difference in the training loads among athletes with and without exercise-induced bronchoconstriction. Methods: This was a cross-sectional study involving elite long-distance runners with neither current asthma symptoms nor a diagnosis of exercise-induced bronchoconstriction. All of the participants underwent eucapnic voluntary hyperpnea challenge and maximal cardiopulmonary exercise tests, as well as completing questionnaires regarding asthma symptoms and physical activity, in order to monitor their weekly training load. Results: Among the 86 male athletes recruited, participation in the study was agreed to by 20, of whom 5 (25%) were subsequently diagnosed with exercise-induced bronchoconstriction. There were no differences between the athletes with and without exercise-induced bronchoconstriction regarding anthropometric characteristics, peak oxygen consumption, baseline pulmonary function values, or reported asthma symptoms. The weekly training load was significantly lower among those with exercise-induced bronchoconstriction than among those without. Conclusions: In this sample of long-distance runners in Brazil, the prevalence of exercise-induced bronchoconstriction was high.

Keywords: Athletes; Asthma, exercise-induced; Exercise test.

Background: The relationship between asthma and gastroesophageal reflux is, as yet, not completely understood. Among the mechanisms thought to be responsible for gastroesophageal reflux-related worsening of asthma symptoms are the vagovagal reflex and microaspiration. Objective: To assess forced expiratory volume in one second after acid infusion. Method: This study investigated the effect of acid infusion in 13 volunteers with moderate asthma and gastroesophageal reflux. Spirometry was performed before and after insertion of an 8F nasogastric tube and a pH meter. After 15 minutes of saline solution infusion into the midpoint between the upper esophageal sphincter and lower esophageal sphincter, and again after 15 minutes of esophageal acidification (with hydrochloric acid) of the same area, forced expiratory volume in one second was reassessed. Acidification was repeated every 5 minutes until forced expiratory volume in one second values stabilized (variation: < 5%). Results: Mean forced expiratory volume in one second values remained stable during the tube insertion, saline infusion, initial hydrochloric acid infusion and subsequent hydrochloric acid infusion procedures (p = 0.72). Lower forced expiratory volume in one second values were seen resulting from the tube insertion in two patients (drops of 11% and 22%, respectively), after saline infusion in another two (drops of 13% and 14%) and after acid infusion in 1 (a drop of 22%). Conclusion: Esophageal acidification over short periods does not lead to spirometric alterations in a group of asthmatics with gastroesophageal reflux. However, in some cases, simple esophageal procedures or infusions result in bronchospasm.

Keywords: Key words: Asthma. Gastroesophageal reflux. Respiratory function tests. Endoscopy/methods.