Blood PressureNCT06229873
Smartphone App-guided Inspiratory Muscle Strength Training for Lowering Systolic Blood Pressure
A study testing App-Based Inspiratory Muscle Strength Training and Clinic-Based Inspiratory Muscle Strength Training in people with Blood Pressure and Vascular Function, run by University of Colorado, Boulder at 1 site in United States.
Trial summary
This clinical trial aims to assess the efficacy of inspiratory muscle strength training (IMST) guided by a smartphone app vs. IMST delivered in a clinical research setting for lowering systolic blood pressure in adults 18 years and older with elevated blood pressure. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Blood Pressure, Vascular Function, Adherence, Treatment
- What is being tested?
- App-Based Inspiratory Muscle Strength Training and Clinic-Based Inspiratory Muscle Strength Training
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 33 participants
- Where
- 1 siteUnited States
- Study dates
- 27 Jun 2024to 31 Dec 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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 18+ years
- Ability to provide informed consent
- Willing to accept random assignment to condition
- Systolic blood pressure 120-160 mmHg
- Owns an Apple or Android smartphone
- Body mass index <40 kg/m2
Show all 11Show fewer
- Subject report of being weight stable in the prior 3 months (<2 kg weight change) and willing to remain weight stable during the 6-week intervention period
- Subjects taking antihypertensive medications will be included provided they meet the other inclusion criteria, including systolic blood pressure. Medication regimen (prescription and dosing) must be stable for at least 3 months prior to enrollment in the study and must remain stable during the 6-week intervention period. These medications will not be withheld prior to experimental protocols.
- If woman of childbearing age:
- Not pregnant (defined as self-report of pregnancy)
- Willing to be abstinent or use approved contraception (i.e., hormonal contraception, intrauterine devices, barrier methods such as condoms with spermicide, and surgical sterilization) throughout the duration of the study
Who cannot join
- Age <18 years
- Participant report of a chronic overt medical condition (e.g., unstable cardiovascular disease, recent myocardial infarction or stroke, cancer) that may make it unsafe to participate in the study under the discretion of the study Medical Director.
- Inability to abstain from consumption of alcohol for 12 hours on experimental days.
- Report of blood donation within 8 weeks prior to enrolling in the study or unwillingness to abstain from donating blood for 8 weeks after completing the study
- Participant report of current ruptured eardrum or any other current condition of the ear
- Participant report of recent abdominal surgery (past 3 months) or current abdominal hernia
- Participant report of current asthma with very low symptom perception, frequent and severe exacerbations, or abnormally low perception of dyspnea
- Participant report of past or current costochondritis (inflammation of the cartilage that joins the ribs to the breastbone)
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Colorado Boulder
Boulder, Colorado, 80309
About this study
This clinical trial aims to assess the efficacy of inspiratory muscle strength training (IMST) guided by a smartphone app vs. IMST delivered in a clinical research setting for lowering systolic blood pressure in adults 18 years and older with elevated blood pressure. Participants will perform IMST for 5 minutes a day, 6 days a week, for 6 weeks.
Read the detailed description
Having above-normal blood pressure, i.e., ≥120 mmHg systolic blood pressure (SBP) and/or ≥80 mmHg diastolic blood pressure (DBP), increases risk of developing cardiovascular diseases, cognitive decline/dementia, chronic kidney disease, and other chronic health problems. Approximately 60% of all US adults have above-normal BP, primarily driven by above-normal SBP.
Currently, above-normal SBP is the single largest modifiable risk factor for cardiovascular mortality in the United States. Thus, developing novel strategies for lowering SBP is an urgent public health and biomedical research priority.
Guidelines emphasize regular aerobic exercise as a first-line intervention for all stages of above-normal systolic blood pressure (SBP). Current guidelines call for ≥150 minutes of aerobic activity per week. However, only ~50% of US adults meet these aerobic exercise guidelines. The greatest reported barrier to achieving aerobic exercise guidelines is lack of time. High-resistance inspiratory muscle strength training (IMST) is a time-efficient (5 minutes per session) lifestyle intervention consisting of 30 inspiratory maneuvers performed against a high resistance. Preliminary data suggest 6-weeks of IMST performed 6 days/week reduces SBP by 9 mmHg in adults with above-normal SBP (i.e., greater than 120 mmHg) at baseline. Importantly, this reduction in SBP is equal to or greater than the reduction in blood pressure typically achieved with time- and effort-intensive healthy lifestyle strategies like conventional aerobic exercise.
The investigators hope utilizing a smartphone app to guide IMST will promote the translation of IMST for widespread use and improving public health. The investigators will conduct a randomized, controlled, single-blind, parallel group design clinical trial to assess the efficacy of 6-weeks of IMST (55%-75% maximal inspiratory pressure) delivered in the research clinic by the study investigators vs. IMST delivered entirely via a smartphone app without investigator involvement, for lowering resting and home SBP in adults aged 18 years and older with above-normal SBP (120-160 mmHg) at baseline. The investigators will also assess the effect of IMST on endothelial function, large-elastic artery stiffness, and potential mechanisms of action.
- Conditions
- Blood Pressure, Vascular Function, Adherence, Treatment
- Being tested
- App-Based Inspiratory Muscle Strength Training, Clinic-Based Inspiratory Muscle Strength Training
- Keywords
- Inspiratory Muscle Strength Training, Above-normal blood pressure, Smartphone Application, Hypertension
- Medical subject headings
- Treatment Adherence and Compliance, Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
App-Based Inspiratory Muscle Strength TrainingDevice
Participants will perform inspiratory muscle strength training guided by a smartphone application. Participants will perform 30 breaths a day at 75% of maximal inspiratory pressure, 6 days a week, for 6 weeks. All training sessions will be guided by the smartphone application.
Clinic-Based Inspiratory Muscle Strength TrainingDevice
Participants will perform inspiratory muscle strength training guided by researchers. Participants will perform 30 breaths a day at 75% of maximal inspiratory pressure, 6 days a week, for 6 weeks. One training session each week will be performed in the research clinic.
| Study group | Role | What they receive |
|---|---|---|
| App-Based Inspiratory Muscle Strength Training | Experimental | Using a handheld device, participants will perform 30 breaths a day, six days a week, for six weeks. Training will be guided by a smartphone application. Receives: Device: App-Based Inspiratory Muscle Strength Training |
| Clinic-Based Inspiratory Muscle Strength Training | Active comparator | Using a handheld device, participants will perform 30 breaths a day, six days a week, for six weeks. Training will be guided by researchers. Receives: Device: Clinic-Based Inspiratory Muscle Strength Training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change From Baseline in Casual Systolic Blood Pressure
Change in systolic blood pressure at rest in the clinic setting
Measured: 6 weeks
Change From Baseline in Home Systolic Blood Pressure
Change in systolic blood pressure measured at rest in the home
Measured: 6 weeks
Secondary outcomes (3)
Change From Baseline in Endothelial Function
A procedure called brachial artery flow-mediated dilation will be used to assess endothelium-dependent vasodilation. During this procedure a blood pressure cuff will be placed on the forearm and then inflated for 5 minutes to restrict blood flow. During the procedure a video of the brachial artery will be taken with an ultrasound. The video will be analyzed to determine the peak change in the blood vessels diameter. Blood flow response after cuff deflation will also be assessed.
Measured: 6 weeks
Change From Baseline in Maximum Inspiratory Pressure
Participants will use a hand-held breathing device to assess their maximum inspiratory pressure once a week during the intervention. During the maximum inspiratory pressure test, participants will inspire into the device as powerfully as they can. Results from the maximum inspiratory pressure tests will be assessed.
Measured: 6 weeks
Difference in Adherence to Inspiratory Muscle Strength Training
Percentage of days performing inspiratory muscle strength training during the intervention between each group
Measured: 6 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jan 2024
- Study start27 Jun 2024
- Primary completion31 Dec 2025
- Study completion31 Dec 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 Blood PressureStudies of the same condition, open and under way.
- 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
- Model description
- Parallel Assignment
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 33 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Boulder
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Douglas Seals, University of Colorado, Boulder
- Investigators
- Daniel H Craighead, PhD, Principal investigator, University of Colorado, Boulder
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06229873
- Sponsor's protocol ID
- 23-0411
- Status last verified
- Apr 2026
- First submitted
- 16 Jan 2024
- Last updated
- 19 May 2026
- Results posted
- Yes, on ClinicalTrials.gov
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 19 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Smartphone App-guided Inspiratory Muscle Strength Training for Lowering Systolic Blood Pressure
- ClinicalTrials.gov ID
- NCT06229873
- Acronym / sponsor ID
- 23-0411
- Conditions
- Blood Pressure, Vascular Function, Adherence, Treatment
- Keywords
- Inspiratory Muscle Strength Training, Above-normal blood pressure, Smartphone Application, Hypertension
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 33 participants (actual)
- Lead sponsor
- University of Colorado, BoulderUniversity, hospital or other
- Study start
- 27 Jun 2024 (actual)
- Primary completion
- 31 Dec 2025 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 29 Jan 2024 (actual)
- Results
- Posted 19 May 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This clinical trial aims to assess the efficacy of inspiratory muscle strength training (IMST) guided by a smartphone app vs. IMST delivered in a clinical research setting for lowering systolic blood pressure in adults 18 years and older with elevated blood pressure. Participants will perform IMST for 5 minutes a day, 6 days a week, for 6 weeks.
Detailed description
Having above-normal blood pressure, i.e., ≥120 mmHg systolic blood pressure (SBP) and/or ≥80 mmHg diastolic blood pressure (DBP), increases risk of developing cardiovascular diseases, cognitive decline/dementia, chronic kidney disease, and other chronic health problems. Approximately 60% of all US adults have above-normal BP, primarily driven by above-normal SBP.
Currently, above-normal SBP is the single largest modifiable risk factor for cardiovascular mortality in the United States. Thus, developing novel strategies for lowering SBP is an urgent public health and biomedical research priority.
Guidelines emphasize regular aerobic exercise as a first-line intervention for all stages of above-normal systolic blood pressure (SBP). Current guidelines call for ≥150 minutes of aerobic activity per week. However, only ~50% of US adults meet these aerobic exercise guidelines. The greatest reported barrier to achieving aerobic exercise guidelines is lack of time. High-resistance inspiratory muscle strength training (IMST) is a time-efficient (5 minutes per session) lifestyle intervention consisting of 30 inspiratory maneuvers performed against a high resistance. Preliminary data suggest 6-weeks of IMST performed 6 days/week reduces SBP by 9 mmHg in adults with above-normal SBP (i.e., greater than 120 mmHg) at baseline. Importantly, this reduction in SBP is equal to or greater than the reduction in blood pressure typically achieved with time- and effort-intensive healthy lifestyle strategies like conventional aerobic exercise.
The investigators hope utilizing a smartphone app to guide IMST will promote the translation of IMST for widespread use and improving public health. The investigators will conduct a randomized, controlled, single-blind, parallel group design clinical trial to assess the efficacy of 6-weeks of IMST (55%-75% maximal inspiratory pressure) delivered in the research clinic by the study investigators vs. IMST delivered entirely via a smartphone app without investigator involvement, for lowering resting and home SBP in adults aged 18 years and older with above-normal SBP (120-160 mmHg) at baseline. The investigators will also assess the effect of IMST on endothelial function, large-elastic artery stiffness, and potential mechanisms of action.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Parallel Assignment
| Arm | Type | Receives |
|---|---|---|
| App-Based Inspiratory Muscle Strength Training | Experimental | Device: App-Based Inspiratory Muscle Strength TrainingUsing a handheld device, participants will perform 30 breaths a day, six days a week, for six weeks. Training will be guided by a smartphone application. |
| Clinic-Based Inspiratory Muscle Strength Training | Active comparator | Device: Clinic-Based Inspiratory Muscle Strength TrainingUsing a handheld device, participants will perform 30 breaths a day, six days a week, for six weeks. Training will be guided by researchers. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (11 listed)
- Age 18+ years
- Ability to provide informed consent
- Willing to accept random assignment to condition
- Systolic blood pressure 120-160 mmHg
- Owns an Apple or Android smartphone
Key exclusion criteria (8 listed)
- Age <18 years
- Participant report of a chronic overt medical condition (e.g., unstable cardiovascular disease, recent myocardial infarction or stroke, cancer) that may make it unsafe to participate in the study under the discretion of the study Medical Director.
- Inability to abstain from consumption of alcohol for 12 hours on experimental days.
- Report of blood donation within 8 weeks prior to enrolling in the study or unwillingness to abstain from donating blood for 8 weeks after completing the study
- Participant report of current ruptured eardrum or any other current condition of the ear
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 |
|---|---|---|
| App-Based Inspiratory Muscle Strength TrainingParticipants will perform inspiratory muscle strength training guided by a smartphone application. Participants will perform 30 breaths a day at 75% of maximal inspiratory pressure, 6 days a week, for 6 weeks. All training sessions will be guided by the smartphone application. | Device | App-Based Inspiratory Muscle Strength Training |
| Clinic-Based Inspiratory Muscle Strength TrainingParticipants will perform inspiratory muscle strength training guided by researchers. Participants will perform 30 breaths a day at 75% of maximal inspiratory pressure, 6 days a week, for 6 weeks. One training session each week will be performed in the research clinic. | Device | Clinic-Based Inspiratory Muscle Strength Training |
Primary outcome
Change From Baseline in Casual Systolic Blood Pressure
Time frame: 6 weeks
Change in systolic blood pressure at rest in the clinic setting
Change From Baseline in Home Systolic Blood Pressure
Time frame: 6 weeks
Change in systolic blood pressure measured at rest in the home
3 secondary outcomes
Change From Baseline in Endothelial Function
Time frame: 6 weeks
Change From Baseline in Maximum Inspiratory Pressure
Time frame: 6 weeks
Difference in Adherence to Inspiratory Muscle Strength Training
Time frame: 6 weeks
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 May 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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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.
Daniel H Craighead, PhD principal investigator
University of Colorado, Boulder
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing App-Based Inspiratory Muscle Strength Training and Clinic-Based Inspiratory Muscle Strength Training in people with Blood Pressure and Vascular Function, run by University of Colorado, Boulder 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 11 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 19 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. 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 19 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?
Change From Baseline in Casual Systolic Blood Pressure (time frame: 6 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 19 May 2026.