Salbutamol effects on endurance athletes and screening for breathing limits
Physiological, Sensory and Ergogenic Effects of Salbutamol - Implications for Athletic Screening and β2 Agonist Use in Sport
This study will test whether a common asthma inhaler, salbutamol, helps non-asthmatic endurance athletes who experience breathing limits during high-intensity exercise.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 64 (estimated) |
| Ages | 18 Years to 55 Years |
| Sex | All |
| Sponsor | University of British Columbia Academic / other |
| Locations | 1 site (Vancouver, British Columbia) |
| Trial ID | NCT07037511 on ClinicalTrials.gov |
What this trial studies
This interventional study enrolls trained male and female endurance athletes without asthma to receive salbutamol or placebo before standardized high-intensity exercise tests. Participants must have high aerobic capacity (V̇O2max >120% predicted), a BMI between 18 and 30 kg/m2, no recent smoking or cardiopulmonary disease, and will undergo measurements of expiratory flow limitation, FEV1, and exercise duration. The primary hypothesis is that salbutamol will increase exercise duration more in athletes who exhibit expiratory flow limitation (EFL) than in those who do not, and that females may show larger effects due to a higher prevalence of EFL. The goal is to determine whether a specific subgroup of non-asthmatic athletes can gain ventilatory or performance benefits from therapeutic β2-agonist use.
Who should consider this trial
Good fit: Ideal candidates are non-asthmatic adult endurance athletes who currently train or compete, have V̇O2max >120% predicted, BMI 18–30 kg/m2, no recent smoking or cardiopulmonary disease, and can attend in-person testing.
Not a fit: Smokers, people with cardiopulmonary disease (other than controlled asthma), recreational or low-fit individuals, and athletes without expiratory flow limitation are unlikely to benefit.
Why it matters
Potential benefit: If successful, the study could identify a subgroup of non-asthmatic endurance athletes who gain measurable breathing and performance benefits from salbutamol, helping to guide clinical care and sports screening policies.
How similar studies have performed: Most prior studies and systematic reviews show no ergogenic benefit of β2-agonists in non-asthmatics at therapeutic doses, though the idea that a small EFL-positive subgroup might benefit is plausible but unproven.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Aerobic capacity (V̇O2max) greater than 120% predicted * Body mass index (BMI) \> 18 and \< 30 kg/m2 * Ability to read and understand English * Currently training and/or competing in endurance sports (i.e. running or cycling) Exclusion Criteria: * Smoking history or currently smoking. Currently smoking is defined as regular use of cigarettes or cannabis at any point in the past year. History of smoking is defined as smoking more than 1 pack year for cigarettes or the equivalent in cannabis use measured as puffs per day / 200 (number of puffs in a pack of cigarettes). * Use of cannabis within the past 30 days or has a smoking history of at least 1 pack year. * Use of vaping devices or e-cigarettes in the past 30 days, or has used them more than 10 times in their lifetime. * History or current symptoms of cardiopulmonary disease (excluding controlled asthma) * Contraindications to exercise testing defined as anything that would prevent exercise under proper and safe conditions (e.g., a problem with the heart or lungs, muscle) * Neuromuscular or musculoskeletal condition
Where this trial is running
Vancouver, British Columbia
- St. Paul's Hospital — Vancouver, British Columbia, Canada (Recruiting)
Study contacts
- Principal investigator: Jordan A Guenette, PhD — University of British Columbia
- Study coordinator: Satvir S Dhillon, MSc
- Email: satvir.dhillon@hli.ubc.ca
- Phone: 604-806-8835
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.