This thesis addresses the performance enhancing effects of β2-agonists (asthma medication) with emphasis on terbutaline in the context of doping. Given the high prevalence of asthma in the athletic population, β2-agonists are among the most used drugs in competitive sport.

While there is consensus that therapeutic inhalation of β2-agonists is without performance enhancing effects, oral β2-agonists are considered performance-enhancing. Since the systemic uptake of inhaled β2-agonists is higher than after oral intake, it may be that high dose inhalation of β2-agonists is performance enhancing. Moreover, the underlying mechanisms by which β2-agonists affect performance in humans are inadequately explored.

The purpose of this PhD was to investigate acute and chronic effects of high dose administration of terbutaline and to examine underlying mechanisms by which terbutaline affects performance.