The Effects of Inhaled Terbutaline on 3-km Running Time-Trial Performance

Terbutaline is a prohibited drug except for athletes with a therapeutic use exemption certificate; terbutaline’s effects on endurance performance are relatively unknown.

Purpose:

Eight males (24.3±2.4yrs; 77.6±8kg; 179.5±4.3cm) and eight females (22.4±3yrs; 58.6±6kg; 163±9.2cm) free from respiratory disease and illness provided written informed consent. Participants completed 3 km running time-trials on a non-motorised treadmill on three separate occasions following placebo, 2 mg or 4 mg inhaled terbutaline, in a single-blind, repeated-measures design. Urine samples (15mins post-exercise) were analysed for terbutaline concentration. Data were analysed using one-way repeated measures ANOVA, significance was set at p<0.05 for all analyses.

Results:

Therapeutic dosing of terbutaline does not lead to an improvement in 3 km running performance despite significantly increased FEV1. Our findings suggest that athletes using inhaled terbutaline at high therapeutic doses to treat asthma will not gain an ergogenic advantage during 3 km running performance.