The effect of salbutamol on performance was studied in 7 male non-asthmatic elite (VO2max ≥ 60 ml/kg/min) athletes. The subjects entered the study just prior to their competitive season. Salbutamol (2 puffs=200 μg) or placebo was administered by metered-dose inhaler, through a spacer device, 20 minutes prior to testing in a double-blind, randomized crossover design. Pulmonary functions including maximum flow volume curves were performed on the first two visits, at 5 intervals (pre-medication, 20 minutes post-medication, and 5, 10, and 20 minutes post-exercise). The first two sessions combined these pulmonary function measures with an exercise bout consisting of a continuously ramped cycle ergometer ride to exhaustion to determine maximal oxygen uptake (VO2max) peak power, and maximal heart rate. Pulse oximetry was used to measure the oxygen saturation of hemoglobin. The next sessions involved performing a 45 minute ride at 70% of VO2max, followed by a timed sprint to exhaustion. Lastly, a Wingate anaerobic test was used to measure total work and peak power.
There was a non-significant decrease in VO2max from a mean of 63.5 ml/kg/min (± 3.2) for the placebo (P) trial, to a mean of 62.6 (± 3.3) with salbutamol (S). No difference was found in peak power (P= 438 Watts ±26.3, S= 438 ±27.9) or maximum heart rate (P=191 beats/min ±5.4, S=191 ±6.0). The performance related variables of endurance sprint time (P=104 seconds ±22.8, S= 97 ±31.4), and Wingate peak power (P= 10.12 Watts/kg ±0.57, S= 9.97 ±0.60) showed a non-significant decrease, while the total work performed on the Wingate test (P= 19.30 kJ ±2.09, S= 19.61 ±1.54) displayed a non-significant increase. The data failed to show significance despite using statistical analysis with a level of significance of p<0.20 to maximize the power of the tests.
There was a statistically significant (p<0.05) increase in post medication (pre-exercise) forced expiratory volume (FEV₁) of 4.5% with salbutamol. This baseline increase persisted post-exercise, but there was no interaction effect of salbutamol and placebo over time. This represents an expected effect in non-asthmatic individuals, and although statistical significance was achieved, the magnitude of difference is not considered to be clinically significant.
It was concluded that a therapeutic dose of aerosol salbutamol does not have an ergogenic effect in elite non-asthmatic athletes and it is therefore recommended that inhaled salbutamol continue to be permitted in international competition for individuals with exercise induced asthma.