Sarah Koch1, Martin J MacInnis1, Benjamin C Sporer2, James L Rupert1, Michael S Koehle3. 1. School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada. 2. Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada Canadian Sport Institute, Vancouver, British Columbia, Canada. 3. School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
Abstract
RATIONALE: Salbutamol may affect lung function and exercise performance differently in individuals with and without asthma. OBJECTIVES: To compare the effects of inhaled salbutamol on lung function, exercise performance and respiratory parameters during cycling exercise in athletes with a positive response to a eucapnic voluntary hyperpnoea (EVH+) and negative (EVH-) challenge, indicative of exercise-induced bronchoconstriction. METHODS: In a randomised controlled trial with a crossover design, a total of 49 well-trained male athletes (14 EVH+ and 35 EVH-) performed two simulated 10 km time-trials on a cycle ergometer 60 min after the inhalation of either 400 μg of salbutamol or a placebo. Lung function, assessed by forced expiratory volume in 1 s, was measured immediately before and 30 min after inhalation. Performance was measured by mean power output. MEASUREMENTS & MAIN RESULTS: Despite a significant increase in lung function after the inhalation of salbutamol compared to the placebo (p<0.001), salbutamol did not affect athletes' perceptions of dyspnoea (p>0.05) or leg exertion (p>0.05) during exercise. Salbutamol did not affect mean power output: EVH+ and EVH- athletes averaged 4.0 (0.5) and 4.1 (0.5) W/kg after salbutamol and 4.0 (0.5) W/kg and 4.0 (0.4) W/kg after placebo, respectively (p>0.05 for each comparison). CONCLUSIONS: The inhalation of salbutamol induced a significant increase in resting lung function in EVH+ and EVH- athletes but this improvement in lung function did not translate to improved exercise performance. Salbutamol had no discernible effect on key ventilatory and exercise parameters regardless of EVH challenge outcome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
RATIONALE: Salbutamol may affect lung function and exercise performance differently in individuals with and without asthma. OBJECTIVES: To compare the effects of inhaled salbutamol on lung function, exercise performance and respiratory parameters during cycling exercise in athletes with a positive response to a eucapnic voluntary hyperpnoea (EVH+) and negative (EVH-) challenge, indicative of exercise-induced bronchoconstriction. METHODS: In a randomised controlled trial with a crossover design, a total of 49 well-trained male athletes (14 EVH+ and 35 EVH-) performed two simulated 10 km time-trials on a cycle ergometer 60 min after the inhalation of either 400 μg of salbutamol or a placebo. Lung function, assessed by forced expiratory volume in 1 s, was measured immediately before and 30 min after inhalation. Performance was measured by mean power output. MEASUREMENTS & MAIN RESULTS: Despite a significant increase in lung function after the inhalation of salbutamol compared to the placebo (p<0.001), salbutamol did not affect athletes' perceptions of dyspnoea (p>0.05) or leg exertion (p>0.05) during exercise. Salbutamol did not affect mean power output: EVH+ and EVH- athletes averaged 4.0 (0.5) and 4.1 (0.5) W/kg after salbutamol and 4.0 (0.5) W/kg and 4.0 (0.4) W/kg after placebo, respectively (p>0.05 for each comparison). CONCLUSIONS: The inhalation of salbutamol induced a significant increase in resting lung function in EVH+ and EVH- athletes but this improvement in lung function did not translate to improved exercise performance. Salbutamol had no discernible effect on key ventilatory and exercise parameters regardless of EVH challenge outcome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Authors: Filip Eckerström; Christian Emil Rex; Marie Maagaard; Sune Rubak; Vibeke Elisabeth Hjortdal; Johan Heiberg Journal: BMJ Open Sport Exerc Med Date: 2018-08-30