THE EFFECT OF SALBUTAMOL ON LUNG FUNCTION AND EXERCISE PERFORMANCE IN ENDURANCE ATHLETES

Abstract

1836 Beta-2-sympathicomimetica are common drugs in the treatment of asthma and exercise induced asthma (EIA). In athletes management of these diseases may be complicated since most beta-2-sympathicomimetica are on the IOC list of banned substances. The aim of this study was to investigate the effects of oral salbutamol administration on lung function and exercise performance. Fifteen well trained, competitive non-asthmatic male cyclists or triathletes (age 22.8±2.0 years, height 182±8 cm, weight 71.1±5.9 kg, training experience 5.7±1.7 years, 13.7±4.2 training hours/week) participated in the study, with a double-blind, randomised, cross-over design. To exclude asthma and EIA all subjects underwent a pulmonary function test before the start of the study. A highly reproducible sport-related time trial exercise test was used to measure performance. During the time trial a fixed amount of work, equivalent to approximately 40 km cycling, had to be performed. Performance was measured by the time needed to complete the trial. Two hours prior to the time trial the subjects took in random order either a single oral dose of 4 mg salbutamol or placebo. Pre-exercise salbutamol increased the peakflow significantly (p<0.05) compared to placebo(11.2±1.2 I/sec versus 1.9±1.3 I/sec). No significant changes in lung function between salbutamol and placebo were found post-exercise. Performance time with salbutamol did not significantly differ from the time needed with placebo (64.1±3.9 versus 62.9±2.7 minutes, respectively). This study demonstrates that a single oral dose of 4 mg salbutamol enhances pulmonary function, but does not improve endurance exercise performance in young healthy non-asthmatic endurance athletes during a 40 km time trial.