The effect of formoterol on blood, urine and muscle metabolism, prolonged endurance performance and sprinting ability in trained endurance athletes

Code: 242C05PB

Beta2-agonists are commonly used by elite endurance athletes to counteract asthma and exercise-induced bronchoconstriction, whereby more than 50% of athletes experience lower airways dysfunction. Inhaling long acting beta2-agonists (such as formoterol) is an efficient administration route that achieves high systemic concentrations and has the potential to be ergogenic to exercise performance. Concerningly, recent reports suggest that Olympic athletes who use beta2-agonists outperform their non-user competitors. Therefore, given the potential performance-enhancing and health-related adverse effects of formoterol, WADA has further restricted formoterol intake allowance (2025 WADA Prohibited List) in an attempt to limit the ergogenic effects. Nonetheless, compared to other beta2-agonists, such as salbutamol and terbutaline, the ergogenic potential of formoterol has been less studied. Furthermore, most of the research has focused on short duration, strength and sprint-type exercise, providing minimal data assessing the ergogenic potential of formoterol on endurance events. As such, more research is required to investigate the performance effects of different doses of formoterol that reflect the new 12-hourly dosing intervals and different combinations of divided doses over a 24-hr period. This line of research can confirm whether the 2025 Prohibited List Guidelines are appropriate such that the symptoms of asthma and exercise-induced bronchoconstriction can be minimized, without providing a substantial ergogenic effect on exercise performance. There is also a need to better understand the mechanisms underpinning the performance-induced changes of formoterol administration. Therefore, the aims of this project are to investigate the ergogenic potential (prolonged endurance, and sprint ability) and characterize the resultant blood, muscle and urine metabolite changes induced by different single and divided doses of formoterol administration, compared to a placebo device.