AsthmaNCT07037511
Effects of Salbutamol in Athletes and Implications for Screening and Sports
A study testing Salbutamol in people with Asthma and Healthy, run by University of British Columbia at 1 site in Canada.
Trial summary
β2-Agonists, commonly used to treat asthma, have also been used by athletes to enhance performance, leading to their ban by the International Olympic Committee in 1972. Research has shown non-asthmatics receive no benefit from these drugs at therapeutic dosages; however, many elite athletes still use them, and… Read more about this study
- Who is it for?
- Ages 18 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Asthma, Healthy, Effect of Drug
- What is being tested?
- Salbutamol
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 64 participants
- Where
- 1 siteCanada
- Study dates
- 30 Oct 2025to 31 Dec 2030
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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)
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
St. Paul's Hospital
Vancouver, British Columbia, V6Z1Y6
Alanna Hind, MSc, 604-806-8835, alanna.hind@hli.ubc.ca
Jordan A Guenette, PhD
About this study
Official title: Physiological, Sensory and Ergogenic Effects of Salbutamol - Implications for Athletic Screening and β2 Agonist Use in Sport
β2-Agonists, commonly used to treat asthma, have also been used by athletes to enhance performance, leading to their ban by the International Olympic Committee in 1972. Research has shown non-asthmatics receive no benefit from these drugs at therapeutic dosages; however, many elite athletes still use them, and asthmatic athletes often win more Olympic medals. In some non-asthmatics, β2-agonists may improve breathing limitations during high intensity exercise, which may improve performance. Therefore, we aim to examine if there is a select group of non-asthmatic individuals who experience breathing limitations that may receive benefit from β2-agonists.
Read the detailed description
Purpose:
The purpose of this study is to examine the effects of β2-agonists on exercise performance in non-asthmatic male and female endurance athletes.
Hypothesis:
Our primary hypothesis is that ß2-agonists will improve exercise duration to a greater degree in athletes who experience expiratory flow limitation (EFL) compared to those who do not experience EFL. Additionally, female athletes will, on average, experience greater benefits with ß2-agonists due to a greater prevalence of EFL than males.
Justification:
While β2-agonists have historically been used by athletes as an ergogenic aid, systematic reviews indicate their ineffectiveness in improving aerobic performance. Consequently, the World Anti-Doping Agency (WADA) revised regulations to allow controlled use of specific β2-agonists. Despite a lack of evidence supporting their ergogenic benefits, positive tests for supratherapeutic doses of salbutamol among elite athletes, such as cyclist Chris Froome and cross-country skier Martin Johnsrud Sundby, suggests a belief in their performance-enhancing capabilities. Additionally, there is a physiological rationale for some non-asthmatics to benefit from these drugs. For instance, therapeutic doses of β2-agonists can induce bronchodilation, resulting in a ~5% increase in forced expiratory volume in one second (FEV1) in non-asthmatics. While this level of bronchodilation does not meet the diagnostic threshold for asthma, it holds potential for enhancing ventilatory responses in certain athletes. For example, a subset of non-asthmatic athletes who develop EFL during exercise, characterized by the inability to increase expiratory flows despite increases in expiratory effort, may derive greater benefits if the bronchodilation is sufficient to attenuate EFL. Indeed, experimental reduction of EFL via breathing a helium-oxygen gas mixture improves ventilatory responses, gas exchange, and endurance performance in non-asthmatics. We speculate that non-asthmatics experiencing EFL during exercise are likely to benefit more from β2-agonists than those who do not develop EFL.
Statistical Analysis:
The effects of salbutamol vs. placebo on exercise duration in all participants will be compared using a paired t-test. In all cases, a P-value < 0.05 will be considered statistically significant. A total of 64 participants (32 males and 32 females) will be recruited to adequately assess the effects of salbutamol on exercise tolerance, dyspnea, and related physiological variables.
- Conditions
- Asthma, Healthy, Effect of Drug
- Being tested
- Salbutamol, Placebo
- Keywords
- Exercise Physiology, Expiratory Flow Limitation, Non-Asthmatics, Beta2-Agonists
- Medical subject headings
- Asthma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SalbutamolDrug
Meter-dose inhaler of salbutamol performed using large-volume spacer
PlaceboDrug
Meter-dose inhaler of placebo performed using large-volume spacer
| Study group | Role | What they receive |
|---|---|---|
| Salbutamol inhaler | Active comparator | Participants will take four inhalations of salbutamol, with 60 seconds between each inhalation, totaling a therapeutic dose of 400µg of salbutamol prior to performing an incremental cardiopulmonary exercise test. Receives: Drug: Salbutamol |
| Placebo inhaler | Placebo comparator | Participants will take four inhalations of placebo, with 60 seconds between each inhalation, prior to performing an incremental cardiopulmonary exercise test. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in time to exhaustion following salbutamol inhalation compared to placebo inhalation.
Exercise duration will be measured during a time to exhaustion cardiopulmonary exercise test on a stationary cycle ergometer or treadmill.
Measured: Up to 2 weeks
Sex differences in time to exhaustion following salbutamol inhalation
Exercise duration will be measured during a time to exhaustion cardiopulmonary exercise test on a stationary cycle ergometer or treadmill. Sexes will be compared within modality.
Measured: Up to 2 weeks
Secondary outcomes (4)
To examine the effects of salbutamol on expiratory flow limitation in endurance athletes
Expiratory flow limitation will be assessed by placing the tidal flow-volume loop within the maximal flow-volume loop during incremental cardiopulmonary exercise testing on a stationary cycle ergometer or treadmill.
Measured: Up to 2 weeks
To explore sex differences in dyspnea following salbutamol inhalation.
Dyspnea will be assessed during and after both incremental and time to exhaustion cardiopulmonary exercise testing on a stationary cycle ergometer or treadmill with salbutamol.
Measured: Up to 2 weeks
To examine ventilatory responses of male and female endurance athletes to exercise with salbutamol.
Ventilatory responses will be measured continuously throughout both incremental and time to exhaustion cardiopulmonary exercise testing on a stationary cycle ergometer or treadmill using a metabolic cart.
Measured: Up to 2 weeks
To explore the effects of salbutamol on exercise duration and expiratory flow limitation in both asthmatic and non-asthmatic individuals.
A Eucapnic Voluntary Hyperpnea (EVH) test will be performed to assess airway hyperresponsiveness and classify participants as EVH-positive or EVH-negative. All participants will undergo the same cardiopulmonary exercise testing on a stationary cycle ergometer or a treadmill with salbutamol.
Measured: Up to 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jun 2025
- Study start30 Oct 2025
- Primary completion31 Dec 2029 (estimated)
- Study completion31 Dec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AsthmaStudies of the same condition, open and under way.
- More trials run by University of British ColumbiaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 64 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of British Columbia
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jordan Guenette, University of British Columbia
- Investigators
- Jordan A Guenette, PhD, Principal investigator, University of British Columbia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07037511
- Sponsor's protocol ID
- H24-01838
- Status last verified
- Jun 2025
- First submitted
- 17 Jun 2025
- Last updated
- 13 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Physiological, Sensory and Ergogenic Effects of Salbutamol - Implications for Athletic Screening and β2 Agonist Use in Sport
- ClinicalTrials.gov ID
- NCT07037511
- Acronym / sponsor ID
- H24-01838
- Conditions
- Asthma, Healthy, Effect of Drug
- Keywords
- Exercise Physiology, Expiratory Flow Limitation, Non-Asthmatics, Beta2-Agonists
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 64 participants (estimated)
- Lead sponsor
- University of British ColumbiaUniversity, hospital or other
- Study start
- 30 Oct 2025 (actual)
- Primary completion
- 31 Dec 2029 (estimated)
- Study completion
- 31 Dec 2030 (estimated)
- First posted
- 25 Jun 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
β2-Agonists, commonly used to treat asthma, have also been used by athletes to enhance performance, leading to their ban by the International Olympic Committee in 1972. Research has shown non-asthmatics receive no benefit from these drugs at therapeutic dosages; however, many elite athletes still use them, and asthmatic athletes often win more Olympic medals. In some non-asthmatics, β2-agonists may improve breathing limitations during high intensity exercise, which may improve performance. Therefore, we aim to examine if there is a select group of non-asthmatic individuals who experience breathing limitations that may receive benefit from β2-agonists.
Detailed description
Purpose:
The purpose of this study is to examine the effects of β2-agonists on exercise performance in non-asthmatic male and female endurance athletes.
Hypothesis:
Our primary hypothesis is that ß2-agonists will improve exercise duration to a greater degree in athletes who experience expiratory flow limitation (EFL) compared to those who do not experience EFL. Additionally, female athletes will, on average, experience greater benefits with ß2-agonists due to a greater prevalence of EFL than males.
Justification:
While β2-agonists have historically been used by athletes as an ergogenic aid, systematic reviews indicate their ineffectiveness in improving aerobic performance. Consequently, the World Anti-Doping Agency (WADA) revised regulations to allow controlled use of specific β2-agonists. Despite a lack of evidence supporting their ergogenic benefits, positive tests for supratherapeutic doses of salbutamol among elite athletes, such as cyclist Chris Froome and cross-country skier Martin Johnsrud Sundby, suggests a belief in their performance-enhancing capabilities. Additionally, there is a physiological rationale for some non-asthmatics to benefit from these drugs. For instance, therapeutic doses of β2-agonists can induce bronchodilation, resulting in a ~5% increase in forced expiratory volume in one second (FEV1) in non-asthmatics. While this level of bronchodilation does not meet the diagnostic threshold for asthma, it holds potential for enhancing ventilatory responses in certain athletes. For example, a subset of non-asthmatic athletes who develop EFL during exercise, characterized by the inability to increase expiratory flows despite increases in expiratory effort, may derive greater benefits if the bronchodilation is sufficient to attenuate EFL. Indeed, experimental reduction of EFL via breathing a helium-oxygen gas mixture improves ventilatory responses, gas exchange, and endurance performance in non-asthmatics. We speculate that non-asthmatics experiencing EFL during exercise are likely to benefit more from β2-agonists than those who do not develop EFL.
Statistical Analysis:
The effects of salbutamol vs. placebo on exercise duration in all participants will be compared using a paired t-test. In all cases, a P-value < 0.05 will be considered statistically significant. A total of 64 participants (32 males and 32 females) will be recruited to adequately assess the effects of salbutamol on exercise tolerance, dyspnea, and related physiological variables.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Salbutamol inhaler | Active comparator | Drug: SalbutamolParticipants will take four inhalations of salbutamol, with 60 seconds between each inhalation, totaling a therapeutic dose of 400µg of salbutamol prior to performing an incremental cardiopulmonary exercise test. |
| Placebo inhaler | Placebo comparator | Drug: PlaceboParticipants will take four inhalations of placebo, with 60 seconds between each inhalation, prior to performing an incremental cardiopulmonary exercise test. |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- 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)
Key exclusion criteria (6 listed)
- 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)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SalbutamolMeter-dose inhaler of salbutamol performed using large-volume spacer | Drug | Salbutamol inhaler |
| PlaceboMeter-dose inhaler of placebo performed using large-volume spacer | Drug | Placebo inhaler |
Primary outcome
Difference in time to exhaustion following salbutamol inhalation compared to placebo inhalation.
Time frame: Up to 2 weeks
Exercise duration will be measured during a time to exhaustion cardiopulmonary exercise test on a stationary cycle ergometer or treadmill.
Sex differences in time to exhaustion following salbutamol inhalation
Time frame: Up to 2 weeks
Exercise duration will be measured during a time to exhaustion cardiopulmonary exercise test on a stationary cycle ergometer or treadmill. Sexes will be compared within modality.
4 secondary outcomes
To examine the effects of salbutamol on expiratory flow limitation in endurance athletes
Time frame: Up to 2 weeks
To explore sex differences in dyspnea following salbutamol inhalation.
Time frame: Up to 2 weeks
To examine ventilatory responses of male and female endurance athletes to exercise with salbutamol.
Time frame: Up to 2 weeks
To explore the effects of salbutamol on exercise duration and expiratory flow limitation in both asthmatic and non-asthmatic individuals.
Time frame: Up to 2 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Mar 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jordan A Guenette, PhD principal investigator
University of British Columbia
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Salbutamol in people with Asthma and Healthy, run by University of British Columbia at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Satvir S Dhillon, MSc (604-806-8835, satvir.dhillon@hli.ubc.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Difference in time to exhaustion following salbutamol inhalation compared to placebo inhalation. (time frame: Up to 2 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Mar 2026.