Can asthma treatment in sports be doping? The effect of the rapid onset, long-acting inhaled beta(2)-agonist formoterol upon endurance performance inhealthy well-trained athletes

Inhaled beta (2)-agonists have been subject to restrictions in relationship to sports due to fear of possible improvement in endurance performance. Ac cording to the international doping regulations only inhaled salbutamol, te rbutaline and salmeterol are allowed for use in sports. Formoterol is a rec ently introduced rapid onset-long-acting inhaled beta (2)-agonist. The main aim of the present randomized, double-blind placebo-controlled stu dy was to investigate possible improvement in endurance performance of inha led formoterol in 24 healthy well-trained competitive male athletes, 21-29 years old. Lung function (flow-volume loops) was measured before, 15 min after each in haled study drug and before and repeatedly after exercise. On day 1, maximu m oxygen uptake (VO2max), peak ventilation (VEpeak) and running time till e xhaustion were measured and used to determine the exercise load on days 2 a nd 3. On days 2 and 3 the subjects inhaled the study drugs, rested for 1 h, then exercised, and VO2max, VEpeak and running time until exhaustion were determined. Inhaled formoterol did not improve any parameter of endurance performance. On the other hand a statistically significant, although not clinically sign ificant (0.05 ml(-1)minkg(-1)), change was found in estimated difference of VO2max between formoterol and placebo in favour of placebo. Lung function increased significantly after inhaled formoterol, and after exercise also f or placebo, but without differences between the beta (2)-agonist and placeb o after exercise. In conclusion, inhaled formoterol did not improve endurance performance com pared to placebo.