Exercise Induced BronchospasmIMT_EIBNCT06336681
Inspiratory Muscle Training on The Severity of Exercise-Induced Bronchoconstriction and Time-Trial Performance (IMT_EIB)
A study testing PrO2Fit Device in people with Exercise Induced Bronchospasm and Exercise Induced Asthma, run by Indiana University at 1 site in United States.
Trial summary
Due to the lack of studies examining the impact of inspiratory muscle training (IMT) on the severity of exercise-induced bronchoconstriction (EIB) and exercise performance, the specific aim of this study is to assess the efficacy of flow-resistive IMT on EIB severity and symptoms, short-acting beta-2-agonist… Read more about this study
- Who is it for?
- Ages 18 to 35 years
- Conditions the study is for
- Exercise Induced Bronchospasm, Exercise Induced Asthma
- What is being tested?
- PrO2Fit Device
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 15 participants
- Where
- 1 siteUnited States
- Study dates
- 10 Feb 2022to 30 Apr 2025
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 35 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Male and female, between the ages of 18 to 35 years.
- Required to be a competitive recreational or college athlete and have at least 1-2 years of cycling or biking experience.
- Body Mass Index (BMI) of 18.5 to 28 kg/m^2
- Considered "moderately to highly active" by the International Physical Activity Questionnaire (IPAQ).
- Have clinically treated mild to moderate persistent asthma and/or exercise-induced bronchoconstriction (EIB), with a resting forced expiratory volume in 1 second (FEV1) > 65% of predicted.
- A ≥ 10% drop in FEV1 after eucapnic voluntary hyperpnea (EVH).
- Prescribed short-acting β2-agonists (SABAs) by a physician.
- Comfortable not taking SABA before experimental visits.
Who cannot join
- History of smoking or recreational smoking, cardiovascular disease, renal disease, neurological disease, and metabolic disease.
- Currently taking asthma maintenance medications (e.g., corticosteroids and leukotriene modifiers)
- Any injuries in the past 6 months.
- Taking selective serotonin reuptake inhibitors (SSRI)'s (antidepressants and anxiety medication), attention-deficit hyperactivity disorder (ADHD) medication, and chronically consume pain medication (Aleve, Tylenol, cannabidiol (CBD), etc.).
- Has had or is positive for COVID-19.
- Resting blood pressure of > 130 mmHg systolic or 90 mmHg diastolic.
- Resting Pulse rate of > 100 bpm.
- Regularly consuming fish oil supplements or eating more then one fish meal per week
Trial locations and contacts
1 site in 1 country.
United States1 site
School of Public Health-Bloomington
Bloomington, Indiana, 47405
About this study
Official title: Effect of Flow-Resistive Inspiratory Muscle Training on The Severity of Exercise-Induced Bronchoconstriction and Cycling Time-Trial Performance
Due to the lack of studies examining the impact of inspiratory muscle training (IMT) on the severity of exercise-induced bronchoconstriction (EIB) and exercise performance, the specific aim of this study is to assess the efficacy of flow-resistive IMT on EIB severity and symptoms, short-acting beta-2-agonist medication use, operating lung volumes, respiratory and limb locomotor muscle deoxygenation during constant-load cycling exercise, exertional dyspnea, and cycling time-trial performance.
Read the detailed description
To the investigators knowledge, no study has been conducted assessing the impact of inspiratory muscle training (IMT) on exercise-induced bronchoconstriction (EIB) severity, exertional dyspnea, and cycling time-trial performance. A review noted that studies examining the impact of IMT on asthma have all demonstrated an increase in inspiratory muscle strength (maximal inspiratory pressure, MIP) and endurance (sustained maximal inspiratory pressure). In addition, it has been observed that the reduction in the perception of dyspnea following and during exercise leads to a reduction in short-acting beta-2-agonist (SABA) use and fewer asthma symptoms. The same review also noted the lack of data available to explain the impacts of IMT on exercise performance and tolerance in athletes with EIB. Due to the lack of studies examining the impact of IMT on the severity of EIB and exercise performance, the specific aim of this study is to assess the efficacy of flow-resistive IMT on EIB severity and symptoms, SABA medication use, operating lung volumes, respiratory and limb locomotor muscle deoxygenation during constant-load cycling exercise, femoral blood flow, exertional dyspnea, and cycling time-trial performance. It is hypothesized that eight weeks of IMT will reduce EIB's severity and symptoms, respiratory and limb locomotor muscle deoxygenation, improve operating lung volumes, and exertional dyspnea and improve cycling time-trial performance.
- Being tested
- PrO2Fit Device
- Medical subject headings
- Asthma, Exercise-Induced
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PrO2Fit DeviceDevice
Also called Flow-resistive inspiratory muscle training, Sham-Flow-resistive inspiratory muscle training
The flow-resistive protocol using the device requires participants to maximally inhale as hard as they can and as long as they can against a small leak (2mm diameter hole) until task failure. This records maximum inspiratory pressure (MIP) and sustained maximal inspiratory pressure (SMIP) values which will be recorded and the best is chosen for the software template by the participant to continue their training session (previously described in arm/group description). The use of the device occurs three times a week, and used for 6-8 weeks.
| Study group | Role | What they receive |
|---|---|---|
| Inspiratory Muscle Training (IMT) group | Experimental | The test protocol requires participants to inhale maximally (maximum inspiratory pressure, MIP) against 2mm diameter leak and sustain inhalation (sustained maximal inspiratory pressure, SMIP) until task failure. Participants will complete 3 SMIP maneuvers with each training session and use the best of the three for that day's training template (corresponding to about 80% SMIP for the IMT group) via the PrO2Fit software. Participants must match or exceed the SMIP template with each increasing level of the work-rest ratio. Work at each level consists of 6 breaths, 36 breaths total. If six breaths are completed, the next level starts. Rest intervals will progressively shorten as training continues from 40-seconds to 5-seconds. The session will be terminated if participants are unable to match at least 90% of the training template for two consecutive breaths or have completed all 36 breaths. Training will be done 3 times a week, and over 8-weeks. Receives: Device: PrO2Fit Device |
| Sham Inspiratory Muscle Training (Sham-IMT) group | Sham comparator | Similar to the IMT group protocol, participants will be required to complete 3 SMIP maneuvers with each training session. Participants will use the best of the three for that day's training template (corresponding to about 30% SMIP for the Sham-IMT group) via the PrO2Fit software. Participants must match or exceed the SMIP template with each increasing level of the work-rest ratio. Work at each level consists of 6 breaths, 36 breaths total. If six breaths are completed, the next level starts. Rest intervals will progressively shorten as training continues from 40-seconds to 30-, 20-, 15-, 10-, and 5-seconds. The training session will be terminated if participants are unable to match at least 90% of the training template for two consecutive breaths or have completed all 36 breaths. Training will be done 3 times a week, and over 8-weeks. Receives: Device: PrO2Fit Device |
What is being measured
The primary outcome is the main question the study is designed to answer.
Exercise-Induced Bronchoconstriction (EIB) Severity
More specifically, the pre- and post-values of the percentage drop in forced expiratory volume in 1 second (FEV1) from the eucapnic voluntary hyperpnea (EVH) test before and after IMT will be measured. Percentage drop in forced expiratory volume in 1 second (FEV1) will be reported in percentages.
Measured: 8 weeks
Maximum Inspiratory Pressure
More specifically, the pre- to post-values of maximum inspiratory pressure (reported as cmH2O) before and after IMT will be measured.
Measured: 8 weeks
Sustained Maximum Inspiratory Pressure
More specifically, the pre- to post-values of sustained maximum inspiratory pressure (reported as pressure time units) before and after IMT will be measured.
Measured: 8 weeks
16-km Cycling Time-Trial Time to Completion
More specifically, differences in 16-km cycling time-trial completion time (seconds) before and after IMT.
Measured: 8 weeks
16-km Cycling Time-Trial Power Output
More specifically, differences in 16-km cycling time-trial power output (watts) before and after IMT.
Measured: 8 weeks
Constant Load 1 and 2 Speed
More specifically, differences in constant load performance (i.e., speed) before and after IMT.
Measured: 8 weeks
Secondary outcomes (8)
Perception of Breathing Intensity, Unpleasantness, and Leg Fatigue During Constant Load 1
More specifically, whether IMT affects an individual's perception of exertional dyspnea (revised Borg Scales from 0-10 to rate breathing intensity and unpleasantness) and revised Borg Scales from 0-10 to rate leg fatigue during constant load 1 (CL1) cycling. Scores will be reported as whole numbers between 0-10. Higher scores indicate extreme intensity, unpleasantness, or fatigue.
Measured: 8 weeks
Perception of Breathing Intensity, Unpleasantness, and Leg Fatigue During Constant Load 2
More specifically, whether IMT affects an individual's perception of exertional dyspnea (revised Borg Scales from 0-10 to rate breathing intensity and unpleasantness) and revised Borg Scales from 0-10 to rate leg fatigue during constant load 2 (CL2) cycling. Scores will be reported as whole numbers between 0-10. Higher scores indicate extreme intensity, unpleasantness, or fatigue.
Measured: 8 weeks
Perception of Breathing Intensity, Unpleasantness, and Leg Fatigue During Time-Trial Cycling
More specifically, whether IMT affects an individual's perception of exertional dyspnea (revised Borg Scales from 0-10 to rate breathing intensity and unpleasantness) and revised Borg Scales from 0-10 to rate leg fatigue during a 16-km cycling time-trial. Scores will be reported as whole numbers between 0-10. Higher scores indicate extreme intensity, unpleasantness, or fatigue.
Measured: 8 weeks
Deoxygenation of the Respiratory and Limb Locomotor Muscles During Constant Load 1
More specifically, the effects of IMT on the deoxygenation (HHb) of the respiratory (RM) and limb locomotor muscles (LM) during constant load 1 (CL1) cycling
Measured: 8 weeks
Deoxygenation of the Respiratory and Limb Locomotor Muscles During Constant Load 2
More specifically, the effects of IMT on the deoxygenation of the respiratory and limb locomotor muscles during constant load 2 (CL2) cycling
Measured: 8 weeks
Deoxygenation of the Respiratory and Limb Locomotor Muscles During Time-Trial Cycling
More specifically, the effects of IMT on the deoxygenation of the respiratory and limb locomotor muscles during a 16-km cycling time-trial
Measured: 8 weeks
Femoral Blood Flow of the Limb Locomotor Muscles During Constant Load 1
More specifically, the effects of IMT on femoral blood flow (FBF) of the limb locomotor muscles during constant load 1 (CL1) cycling
Measured: 8 weeks
Femoral Blood Flow of the Limb Locomotor Muscles During Constant Load 2
More specifically, the effects of IMT on femoral blood flow (FBF) of the limb locomotor muscles during constant load 2 (CL2) cycling
Measured: 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Mar 2024
- Study start10 Feb 2022
- Primary completion30 Apr 2025
- Study completion30 Apr 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Exercise Induced BronchospasmStudies of the same condition, open and under way.
- More trials run by Indiana UniversityThe 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- Indiana University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tim Mickleborough, Indiana University
- Investigators
- Tim Mickleborough, Ph.D., Principal investigator, Indiana University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06336681
- Sponsor's protocol ID
- #12966
- Acronym
- IMT_EIB
- Status last verified
- May 2025
- First submitted
- 7 Mar 2024
- Last updated
- 12 May 2026
- Results posted
- Yes, on ClinicalTrials.gov
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No: The plan to share individual participant data (IPD) is still unknown. However, if other researchers request IPD, we will evaluate that request and determine to share IPD.
Study at a glance
From the registry record, last updated by the sponsor on 12 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Flow-Resistive Inspiratory Muscle Training on The Severity of Exercise-Induced Bronchoconstriction and Cycling Time-Trial Performance
- ClinicalTrials.gov ID
- NCT06336681
- Acronym / sponsor ID
- IMT_EIB / #12966
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- Indiana UniversityUniversity, hospital or other
- Study start
- 10 Feb 2022 (actual)
- Primary completion
- 30 Apr 2025 (actual)
- Study completion
- 30 Apr 2025 (actual)
- First posted
- 29 Mar 2024 (actual)
- Results
- Posted 12 May 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Due to the lack of studies examining the impact of inspiratory muscle training (IMT) on the severity of exercise-induced bronchoconstriction (EIB) and exercise performance, the specific aim of this study is to assess the efficacy of flow-resistive IMT on EIB severity and symptoms, short-acting beta-2-agonist medication use, operating lung volumes, respiratory and limb locomotor muscle deoxygenation during constant-load cycling exercise, exertional dyspnea, and cycling time-trial performance.
Detailed description
To the investigators knowledge, no study has been conducted assessing the impact of inspiratory muscle training (IMT) on exercise-induced bronchoconstriction (EIB) severity, exertional dyspnea, and cycling time-trial performance. A review noted that studies examining the impact of IMT on asthma have all demonstrated an increase in inspiratory muscle strength (maximal inspiratory pressure, MIP) and endurance (sustained maximal inspiratory pressure). In addition, it has been observed that the reduction in the perception of dyspnea following and during exercise leads to a reduction in short-acting beta-2-agonist (SABA) use and fewer asthma symptoms. The same review also noted the lack of data available to explain the impacts of IMT on exercise performance and tolerance in athletes with EIB. Due to the lack of studies examining the impact of IMT on the severity of EIB and exercise performance, the specific aim of this study is to assess the efficacy of flow-resistive IMT on EIB severity and symptoms, SABA medication use, operating lung volumes, respiratory and limb locomotor muscle deoxygenation during constant-load cycling exercise, femoral blood flow, exertional dyspnea, and cycling time-trial performance. It is hypothesized that eight weeks of IMT will reduce EIB's severity and symptoms, respiratory and limb locomotor muscle deoxygenation, improve operating lung volumes, and exertional dyspnea and improve cycling time-trial performance.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Inspiratory Muscle Training (IMT) group | Experimental | Device: PrO2Fit DeviceThe test protocol requires participants to inhale maximally (maximum inspiratory pressure, MIP) against 2mm diameter leak and sustain inhalation (sustained maximal inspiratory pressure, SMIP) until task failure. Participants will complete 3 SMIP maneuvers with each training session and use the best of the three for that day's training template (corresponding to about 80% SMIP for the IMT group) via the PrO2Fit software. Participants must match or exceed the SMIP template with each increasing level of the work-rest ratio. Work at each level consists of 6 breaths, 36 breaths total. If six breaths are completed, the next level starts. Rest intervals will progressively shorten as training continues from 40-seconds to 5-seconds. The session will be terminated if participants are unable to match at least 90% of the training template for two consecutive breaths or have completed all 36 breaths. Training will be done 3 times a week, and over 8-weeks. |
| Sham Inspiratory Muscle Training (Sham-IMT) group | Sham comparator | Device: PrO2Fit DeviceSimilar to the IMT group protocol, participants will be required to complete 3 SMIP maneuvers with each training session. Participants will use the best of the three for that day's training template (corresponding to about 30% SMIP for the Sham-IMT group) via the PrO2Fit software. Participants must match or exceed the SMIP template with each increasing level of the work-rest ratio. Work at each level consists of 6 breaths, 36 breaths total. If six breaths are completed, the next level starts. Rest intervals will progressively shorten as training continues from 40-seconds to 30-, 20-, 15-, 10-, and 5-seconds. The training session will be terminated if participants are unable to match at least 90% of the training template for two consecutive breaths or have completed all 36 breaths. Training will be done 3 times a week, and over 8-weeks. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Male and female, between the ages of 18 to 35 years.
- Required to be a competitive recreational or college athlete and have at least 1-2 years of cycling or biking experience.
- Body Mass Index (BMI) of 18.5 to 28 kg/m^2
- Considered "moderately to highly active" by the International Physical Activity Questionnaire (IPAQ).
- Have clinically treated mild to moderate persistent asthma and/or exercise-induced bronchoconstriction (EIB), with a resting forced expiratory volume in 1 second (FEV1) > 65% of predicted.
Key exclusion criteria (8 listed)
- History of smoking or recreational smoking, cardiovascular disease, renal disease, neurological disease, and metabolic disease.
- Currently taking asthma maintenance medications (e.g., corticosteroids and leukotriene modifiers)
- Any injuries in the past 6 months.
- Taking selective serotonin reuptake inhibitors (SSRI)'s (antidepressants and anxiety medication), attention-deficit hyperactivity disorder (ADHD) medication, and chronically consume pain medication (Aleve, Tylenol, cannabidiol (CBD), etc.).
- Has had or is positive for COVID-19.
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 |
|---|---|---|
| PrO2Fit DeviceAlso: Flow-resistive inspiratory muscle training, Sham-Flow-resistive inspiratory muscle trainingThe flow-resistive protocol using the device requires participants to maximally inhale as hard as they can and as long as they can against a small leak (2mm diameter hole) until task failure. This records maximum inspiratory pressure (MIP) and sustained maximal inspiratory pressure (SMIP) values which will be recorded and the best is chosen for the software template by the participant to continue their training session (previously described in arm/group description). The use of the device occurs three times a week, and used for 6-8 weeks. | Device | Inspiratory Muscle Training (IMT) group, Sham Inspiratory Muscle Training (Sham-IMT) group |
Primary outcome
Exercise-Induced Bronchoconstriction (EIB) Severity
Time frame: 8 weeks
More specifically, the pre- and post-values of the percentage drop in forced expiratory volume in 1 second (FEV1) from the eucapnic voluntary hyperpnea (EVH) test before and after IMT will be measured. Percentage drop in forced expiratory volume in 1 second (FEV1) will be reported in percentages.
Maximum Inspiratory Pressure
Time frame: 8 weeks
More specifically, the pre- to post-values of maximum inspiratory pressure (reported as cmH2O) before and after IMT will be measured.
Sustained Maximum Inspiratory Pressure
Time frame: 8 weeks
More specifically, the pre- to post-values of sustained maximum inspiratory pressure (reported as pressure time units) before and after IMT will be measured.
16-km Cycling Time-Trial Time to Completion
Time frame: 8 weeks
More specifically, differences in 16-km cycling time-trial completion time (seconds) before and after IMT.
16-km Cycling Time-Trial Power Output
Time frame: 8 weeks
More specifically, differences in 16-km cycling time-trial power output (watts) before and after IMT.
Constant Load 1 and 2 Speed
Time frame: 8 weeks
More specifically, differences in constant load performance (i.e., speed) before and after IMT.
8 secondary outcomes
Perception of Breathing Intensity, Unpleasantness, and Leg Fatigue During Constant Load 1
Time frame: 8 weeks
Perception of Breathing Intensity, Unpleasantness, and Leg Fatigue During Constant Load 2
Time frame: 8 weeks
Perception of Breathing Intensity, Unpleasantness, and Leg Fatigue During Time-Trial Cycling
Time frame: 8 weeks
Deoxygenation of the Respiratory and Limb Locomotor Muscles During Constant Load 1
Time frame: 8 weeks
Deoxygenation of the Respiratory and Limb Locomotor Muscles During Constant Load 2
Time frame: 8 weeks
Deoxygenation of the Respiratory and Limb Locomotor Muscles During Time-Trial Cycling
Time frame: 8 weeks
Femoral Blood Flow of the Limb Locomotor Muscles During Constant Load 1
Time frame: 8 weeks
Femoral Blood Flow of the Limb Locomotor Muscles During Constant Load 2
Time frame: 8 weeks
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 May 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No. The plan to share individual participant data (IPD) is still unknown. However, if other researchers request IPD, we will evaluate that request and determine to share IPD.
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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. This study is not recruiting at the moment.
Tim Mickleborough, Ph.D. principal investigator
Indiana University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing PrO2Fit Device in people with Exercise Induced Bronchospasm and Exercise Induced Asthma, run by Indiana University at 1 site in United States.
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 8 inclusion and 8 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: finished, as of the sponsor's last update on 12 May 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 United States. 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?
Yes. Results are posted in the registry (first posted 12 May 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Exercise-Induced Bronchoconstriction (EIB) Severity (time frame: 8 weeks). The study lists 6 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 12 May 2026; AzTrials last refreshed its copy on 7 Nov 2026.