Sports Medicine

, Volume 41, Issue 1, pp 39–57

β2-Agonists and Physical Performance

A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Authors

    • Royal Netherlands Lawn Tennis Association (KNLTB)
  • Olivier de Hon
    • Anti-Doping Authority the Netherlands
  • J. Bart Staal
    • Department of Epidemiology and Caphri Research SchoolMaastricht University
    • Scientific Institute for the Quality of HealthcareRadboud University Medical Centre
  • Jacqueline Limpens
    • Medical Library, Academic Medical Center
    • The Dutch Cochrane Centre
  • Harm Kuipers
    • Department of Movement Sciences, Nutrition and Toxicology Research Institute Maastricht, (NUTRIM)University of Maastricht
  • Shelley E. Overbeek
    • Medical Centre Alkmaar
  • Aeilko H. Zwinderman
    • Department of Clinical Epidemiology, Biostatistics and BioinformaticsAcademic Medical Center
  • Rob J. P. M. Scholten
    • The Dutch Cochrane Centre
    • Department of Clinical Epidemiology, Biostatistics and BioinformaticsAcademic Medical Center
Review Article

DOI: 10.2165/11537540-000000000-00000

Cite this article as:
Pluim, B.M., de Hon, O., Staal, J.B. et al. Sports Med (2011) 41: 39. doi:10.2165/11537540-000000000-00000

Abstract

Inhaled β2-agonists are commonly used as bronchodilators in the treatment of asthma. Their use in athletes, however, is restricted by anti-doping regulations. Controversies remain as to whether healthy elite athletes who use bronchodilators may gain a competitive advantage.

The aim of this systematic review and meta-analysis is to assess the effects of inhaled and systemic β2-agonists on physical performance in healthy, nonasthmatic subjects. To this end, MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched up to August 2009. Reference lists were searched for additional relevant studies. The search criteria were for randomized controlled trials examining the effect of inhaled or systemic β2-agonists on physical performance in healthy, nonasthmatic subjects. Two authors independently performed the selection of studies, data extraction and risk of bias assessment. Parallel-group and crossover trials were analysed separately. Mean difference (MD) and 95% confidence intervals were calculated for continuous data and, where possible, data were pooled using a fixed effects model.

Twenty-six studies involving 403 participants (age range 7–30 years) compared inhaled β2-agonists with placebo. No significant effect could be detected for inhaled β2-agonists on maximal oxygen consumption (V̇O2max) [MD −0.14mL•kg−1•min−1; 95% CI −1.07, 0.78; 16 studies], endurance time to exhaustion at 105–110% V̇O2max (MD −1.5 s; 95% CI −15.6, 12.6; four studies), 20-km time trial duration (MD −4.4 s; 95% CI −23.5, 14.7; two studies), peak power (MD −0.14 W•kg−1; 95% CI −0.54, 0.27; four studies) and total work during a 30-second Wingate test (MD 0.80 J•kg−1; 95% CI −2.44, 4.05; five studies). Thirteen studies involving 172 participants (age range 7–22 years) compared systemic β2-agonists with placebo, with 12 studies involving oral and one study involving intravenous salbutamol. A significant effect was detected for systemic β2-agonists on endurance time to exhaustion at 80–85% V̇O2max (MD 402 s; 95% CI 34, 770; two studies), but not for V̇O2max (placebo 42.5–1.7mL•kg−1•min−1, salbutamol 42.1±2.9mL•kg−1•min−1, one study), endurance time to exhaustion at 70% V̇O2max (MD 400 s; 95%CI −408, 1208; one study) or power output at 90% V̇O2max (placebo 234.9±16 W, salbutamol 235.5±18.1 W, one study). Asignificant effect was shown for systemic β2-agonists on peak power (MD 0.91 W•kg−1; 95% CI 0.25, 1.57; four studies), but not on total work (MD 7.8 J•kg−1; 95% CI −3.3, 18.9; four studies) during a 30-second Wingate test. There were no randomized controlled trials assessing the effects of systemic formoterol, salmeterol or terbutaline on physical performance.

In conclusion, no significant effects were detected for inhaled β2-agonists on endurance, strength or sprint performance in healthy athletes. There is some evidence indicating that systemic β2-agonists may have a positive effect on physical performance in healthy subjects, but the evidence base is weak.

Copyright information

© Adis Data Information BV 2011