Abstract
Introduction Many athletes use short-acting inhaled beta2-agonists multiple times weekly during training sessions to prevent exercise-induced bronchoconstriction, but it is unclear if treatment impairs training outcomes. Herein, we investigated performance adaptations in well-trained females and males training with prior inhalation of salbutamol.
Methods Nineteen females and 21 males with maximal oxygen uptake (VO2max) of 50.5±3.3 and 57.9±4.9 mL·min−1·kg−1 participated in this double-blinded, placebo-controlled, parallel-group study. We randomised participants to placebo or salbutamol inhalation (1600 µg·training day−1) for 6 weeks of combined endurance (1×/week) and high-intensity interval-training (2×/week). We assessed participants’ body composition, VO2max, and muscle contractile function, and collected vastus lateralis muscle biopsies.
Results Salbutamol induced a sex-specific loss of whole-body fat mass (sex×treatment: p=0.048) where only salbutamol-treated females had a fat mass reduction compared to placebo (–0.8 kg at 6 weeks; 95%CI: −0.5 to −1.6; p=0.039). Furthermore, salbutamol-treated females exhibited a repartitioning effect, lowering fat mass while gaining lean mass (p=0.011), which was not apparent for males (p=0.303). Salbutamol negatively impacted VO2max in both sexes (treatment main-effect: p=0.014) due to a blunted increase in VO2max during the initial 4 weeks of the intervention. Quadriceps contractile strength was impaired in salbutamol-treated females (−39 Nm; 95%CI: −61 to −17; p=0.002) compared to placebo at 6 weeks. Muscle electron-transport-chain complex I-V abundance increased with salbutamol (treatment main-effect: p=0.035) while content of SERCAI, beta2-adrenoceptor, and desmin remained unchanged.
Conclusion Inhaled salbutamol appears to be an effective repartitioning agent in females but may impair aerobic and strength related training outcomes.
Footnotes
This manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.
Conflicts of interest: Authors have no conflicting interests.
This is a PDF-only article. Please click on the PDF link above to read it.
- Received September 5, 2023.
- Accepted October 24, 2023.
- Copyright ©The authors 2023
This version is distributed under the terms of the Creative Commons Attribution Non-Commercial Licence 4.0. For commercial reproduction rights and permissions contact permissions{at}ersnet.org
