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Can β2-agonists have an ergogenic effect on strength, sprint or power performance? Systematic review and meta-analysis of RCTs.
- Source :
- British Journal of Sports Medicine; Nov2020, Vol. 54 Issue 22, p1-10, 10p
- Publication Year :
- 2020
-
Abstract
- <bold>Objectives: </bold>We aimed to examine the effect of β2-agonists on anaerobic performance in healthy non-asthmatic subjects.<bold>Design: </bold>Systematic review and meta-analysis.<bold>Eligibility Criteria: </bold>We searched four databases (PubMed, Embase, SPORTDiscus and Web of Science) for randomised controlled trials, published until December 2019, examining the effect of β2-agonists on maximal physical performance lasting 1 min or shorter. Data are presented as standardised difference in mean (SDM) with 95% confidence intervals (95% CI).<bold>Results: </bold>34 studies were included in the present meta-analysis. The studies include 44 different randomised and placebo-controlled comparisons with β2-agonists comprising 323 participants in crossover trials, and 149 participants in parallel trials. In the overall analyses, β2-agonists improved anaerobic performance by 5% (SDM 0.29, 95% CI 0.16 to 0.42), but the effect was related to dose and administration route. In a stratified analysis, the SDM was 0.14 (95% CI 0.00 to 0.28) for approved β2-agonists and 0.46 (95% CI 0.24 to 0.68) for prohibited β2-agonists, respectively. Furthermore, SDM was 0.16 (95% CI 0.02 to 0.30) for inhaled administration and 0.51 (95% CI 0.25 to 0.77) for oral administration, respectively, and 0.20 (95% CI 0.07 to 0.33) for acute treatment and 0.50 (95% CI 0.20 to 0.80) for treatment for multiple weeks. Analyses stratified for the type of performance showed that strength (0.35, 95% CI 0.15 to 0.55) and sprint (0.17, 95% CI 0.06 to 0.29) performance were improved by β2-agonists.<bold>Conclusion/implication: </bold>Our study shows that non-asthmatic subjects can improve sprint and strength performance by using β2-agonists. It is uncertain, however, whether World Anti-Doping Agency (WADA)-approved doses of β2-agonists improve performance. Our results support that the use of β2-agonists should be controlled and restricted to athletes with documented asthma.<bold>Systematic Review Registration: </bold>PROSPERO CRD42018109223. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03063674
- Volume :
- 54
- Issue :
- 22
- Database :
- Complementary Index
- Journal :
- British Journal of Sports Medicine
- Publication Type :
- Academic Journal
- Accession number :
- 146699329
- Full Text :
- https://doi.org/10.1136/bjsports-2019-100708