Sporer, B. C., Sheel, A. W., & McKenzie, D. C. (2008). Dose response of inhaled salbutamol on exercise performance and urine concentrations. Medicine and Science in Sports and Exercise, 40, 149-157.

This study evaluated the dose-response effects of inhaled salbutamol on time-trial performance and urine concentrations of salbutamol. Nonasthmatic, trained male cyclists and triathletes (N = 37) were studied. Day 1 consisted of screening for airway hyper-responsiveness, followed by an incremental exercise test to determine VO2max and peak power (Pmax). On days 2-5, athletes performed a 20-km time trial 15 minutes after inhalation of a placebo, 200 micrograms, 400 micrograms, or 800 micrograms of salbutamol.

Seven Ss had positive responses to the airway hyper-responsiveness test and were excluded from further participation in the study. There was no effect of dose on time-trial completion time, mean power, or mean heart rate. Salbutamol had no effect on any metabolic or ventilatory parameters. The urine concentration of salbutamol increased with dose and was highly variable. Moderate but significant correlations were noted between urine salbutamol and urine specific gravity at higher doses.

Implication. Salbutamol does not enhance time-trial performance, regardless of dose. Urine concentration of salbutamol after exercise is related to dose, demonstrates high variability, and is partially related to hydration status.

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