ABSTRACT
Maximum performance in aerobic events, at whatever level of competition, is only achievable if respiratory function is optimal. Competitors will always be concerned about respiratory problems, be they major diseases (e.g. asthma) or minor ailments (e.g. the common cold). Respiratory function may be compromised in athletes who suffer from long-term medical conditions, such as asthma, for which one of the ¿ rst-line classes of drugs is beta-2 agonists. These drugs produce their therapeutic effect through bronchodilation. Clearly, such an effect has the potential to enhance athletic performance by improving oxygen uptake. However, research in support of such performance enhancement is limited. Nonetheless, beta-2 agonists exist as a category on the World Anti-Doping Agency (WADA) Prohibited List, subject to a complex set of regulations. Because beta-2 agonists are a necessary component in the treatment regimens for patients with asthma, Therapeutic Use Exemptions (TUEs) may be requested for these athletes to allow them to compete on equal terms with fellow competitors. Some beta-2 agonists, such as clenbuterol, possess anabolic properties, although through a mechanism that is different from that produced by anabolic steroids; this is an additional reason for inclusion under the category of anabolic agents on the WADA Prohibited List.
