Beta-2 agonists and exercise performance in humans

• Published in: Science & sports Vol. 25; no. 6; pp. 281 - 290
• Main Authors: Collomp, K, Le Panse, B, Candau, R, Lecoq, A-M, De Ceaurriz, J
• Format: Journal Article
• Language: French
• Published: 01-12-2010
• ISSN: 0765-1597
• DOI: 10.1016/j.scispo.2010.08.002

Due to fears of doping effects, the World Anti-Doping Agency has put certain restrictions on the use of the pharmacological class of beta-2 agonists. In 2010, all beta-agonists are prohibited except salbutamol and salmeterol by inhalation, which require a declaration of use in accordance with the international standard for therapeutic use exemptions. We reviewed the current literature to determine whether inhaled or oral beta-2 agonists enhance human performance and, based on our findings, we present hypotheses on the mechanisms that might account for the documented performance gains. Most of the trials were conducted after acute therapeutic inhalation and generally failed to show improved performance after such local low-dose administration, probably because of a lack of sufficient systemic bioavailability. In contrast, almost all trials after acute or short-term oral administration at therapeutic dosage demonstrated significantly improved performance, whatever the exercise intensity. The mechanisms by which the systemic administration of beta-2 agonists produces ergogenic effects are unknown, but the popular theory that salbutamol has an ergogenic effect due to its anabolic properties can be ruled out. The theory that it enhances substrate oxidation is incomplete, and both central and peripheral effects have been suggested. Further studies are needed with particular focus on: (1) the effects of systemic administration of terbutaline or bambuterolaa; (2) the effects of short-term supratherapeutic inhalation, and (3) the determination of a urinary threshold for terbutaline, salmeterol and formoterol. En raison des possibles effets dopants, l'Agence mondiale antidopage a instaure certaines restrictions concernant l'utilisation des substances appartenant A la classe pharmacologique des b(TM)ta-2aaagonistes. En 2010, tous les b(TM)ta-2aaagonistes sont interdits, A l'exception du salbutamol et du salmeterol par inhalation, ces administrations locales necessitant une declaration d'usage. Nous proposons, A partir de la litterature scientifique actuelle, de faire un etat des lieux des connaissances concernant les effets ergogeniques des b(TM)ta-2aaagonistes. Parallelement, certaines hypotheses A propos des mecanismes d'action potentiellement impliques dans l'amelioration de performance sont presentees. La plupart des etudes ont ete conduites suite A des inhalations de b(TM)ta-2aaagonistes A dose therapeutique et ne mettent pas en evidence d'amelioration de la performance sportive, probablement en raison des faibles doses administrees n'entraA registered nant pas de passage systemique significatif. Au contraire, la quasi-totalite des etudes conduites apres administration orale (par exemple, aiguA' et de courte duree) montrent une amelioration de la performance sportive, quelle que soit l'intensite de l'exercice effectue. Les mecanismes A l'origine de cet effet ergogenique des b(TM)ta-2aaagonistes lors d'une prise systemique restent mal connus, mais celui-ci ne resulte pas d'un effet anabolisant. L'hypothese A'aaenergetiqueA&#16 0; A' ne peut (TM)tre qu'une reponse partielle et un effet des b(TM)ta-2aaagonistes A la fois au niveau central et peripherique doit (TM)tre considere. De nouvelles etudes apparaissent necessaires en particulier afin deaa: (1) determiner les effets ergogeniques d'une prise orale de terbutaline et de bambuterolaa; (2) verifier les repercussions d'une inhalation de courte duree A dose supra-therapeutique et (3) fixer un seuil urinaire de positivite pour la terbutaline, le salmeterol et le formoterol.