β2-agonists in sports: prevalence and impact on athletic performance

Respiratory disorders caused by exercise are expressed in the development of exercise-induced bronchoconstriction (EIB) and exercise-induced asthma (EIA), which are observed in athletes, especially in cyclic sports, much more often than in the population. Ventilation impairments are exacerbated by inhaled allergens, industrial pollutants and adverse environmental conditions, which increase the risk of EIB and asthma symptoms in athletes. The use of β2-agonists can prevent or eliminate ventilation disorders, however, it requires taking into account current anti-doping rules, which allow the use of certain substances in sports without a request for therapeutic use. The studies of the influence of β2-agonists on functional indicators of athletes and sports performance do not allow to make an unambiguous conclusion about its results. Medications with β2-agonists, approved for use in sports in the form of inhalation, do not have a significant effect on the performance of athletes at major sports competitions. At the same time, the systemic use of these substances and the use of any form of terbutaline caused a positive dynamics in functional indicators, which could lead to an illegal increase in the effectiveness of sports performance. Most of the conclusions about the effect of β2-agonists on outcome are based on a small number of studies, their heterogeneity, and an insignificant number of observations. It is necessary to continue studying the effects of β2-agonists in the course of randomized clinical trials in order to individualize therapy and prevent bronchial obstruction in athletes