Effects of Respiratory Muscle Training on Tongue Muscle Function

April 28, 2026 updated by: William Poncin, Université Catholique de Louvain

Effects of Respiratory Muscle Training on Tongue Muscle Function in Healthy Subjects, a Randomized Controlled Trial.

This study aims to investigate the effects of respiratory muscle training on tongue muscle function in healthy subjects. We hypothesize that respiratory muscle training can improve strength and endurance of the tongue muscles.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

In patient with obstructive sleep apnea, studies have shown that respiratory muscle training improved sleep-related outcomes in patients with obstructive sleep apnea (OSA). On the other hand, a recent study showed that expiratory muscle training improved tongue motor strength in patients with OSA. We hypothesize that respiratory muscle training (either Inspiratory Muscle Training (IMT) or Expiratory Muscle Training (EMT)) may elicit sleep-related improvement in patient with OSA through enhancement on tongue muscle function.

To investigate our hypothesis, we will first address this question in a population of healthy subjects. This study will therefore investigate the effects of respiratory muscle training on tongue muscle function in healthy subjects. The primary hypothesis is that the IMT program with lead to an increase in tongue strength compared to the control group. Other hypothesizes are that EMT, but not sham, will also lead to an increase in tongue strength, compared to the control group.

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

Community ambulant adults between 18 to 65 years old as of testing day; able to understand French or Dutch (depending on the study's site of inclusion); BMI ≥ 18 and ≤ 30 kg/m².

Exclusion Criteria:

Any diagnosed neuromuscular or cardiorespiratory disease; diagnosed psychiatric or psychological disorders which could affect adherence to or comprehension of instructions; diagnosed eating disorders; previous or ongoing head and neck cancer; diagnosed OSA; presenting a high-risk of sleep-disordered breathing indicated by a NoSAS score of 8 or higher 32 or a STOP-Bang score of 3 or higher 33,34; resting heart rate (HR) > 100 beats per minute (bpm) or < 50 bpm; resting systolic blood pressure (SBP) > 140 or < 90 mmHg, diastolic blood pressure (DBP) > 90 or < 50 mmHg; oxygen saturation (SpO2) < 94% at rest on room air. Individuals with abnormal lung function, i.e., forced expiratory volume in 1 second (FEV1) ≤ 80%, forced vital capacity (FVC) ≤ 80%, and FEV1/FVC ≤ 70%, will also be excluded.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Control
Sham Comparator: Sham
Device: Sham
A pressure threshold loading device will be used: the POWERbreathe Ex1 EMT Medic or MR, but with the resistance mechanism inside removed and replaced by a plastic ball. The same instructions will be given as for the EMT group, except that there will be no or minimal resistance (less than 6 cmH2O). There will be no change in resistance over the weeks.
Active Comparator: IMT
Device: IMT
Description: A pressure threshold loading device will be used: the POWERbreathe Medic (load range 10-90 cmH2O). Participants will be instructed to exhale passively during normal tidal breathing through the training device (until functional residual capacity) and to perform deep inspirations against the external load. The first week, the resistance will be fixed at 30% of the baseline measured maximal inspiratory pressure (MIP). Participants will be instructed to increase the resistance by 10% of the baseline set resistance each week.
Active Comparator: EMT
Device: EMT
A pressure threshold loading device will be used: the POWERbreathe Ex1 EMT Medic (load range 10-90 cmH2O) or POWERbreathe Ex1 EMT MR (load range 35-175 cmH2O) depending on their baseline MEP measurement. Participants will be instructed to inhale quietly during normal tidal breathing through the training device and to perform rapid and deep exhalation against the external load. The first week, the resistance will be fixed at 30% of the baseline measured MEP. Participants will be instructed to increase the resistance by 10% of the baseline set resistance each week.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Tongue elevation strength
Time Frame: Measured two times: at baseline and after 8 weeks
Tongue elevation strength (peak pressure) will be measured via the Iowa Oral Performance Instrument (IOPI).
Measured two times: at baseline and after 8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Tongue protrustion strength
Time Frame: Measured two times: at baseline and after 8 weeks
Tongue protrusion strength (peak pressure) will be measured via the Iowa Oral Performance Instrument (IOPI).
Measured two times: at baseline and after 8 weeks
Tongue elevation endurance
Time Frame: Measured two times: at baseline and after 8 weeks
Tongue elevation endurance (50% of peak pressure) will be measured via the Iowa Oral Performance Instrument (IOPI).
Measured two times: at baseline and after 8 weeks
Tongue protrusion endurance
Time Frame: Measured two times: at baseline and after 8 weeks
Tongue protrusion endurance (50% of peak pressure) will be measured via the Iowa Oral Performance Instrument (IOPI).
Measured two times: at baseline and after 8 weeks
Maximal inspiratory pressure
Time Frame: Measured two times: at baseline and after 8 weeks
Maximal inspiratory pressure will be measured at functional residual capacity (FRC)
Measured two times: at baseline and after 8 weeks
Maximal expiratory pressure
Time Frame: Measured two times: at baseline and after 8 weeks
Maximal expiratory pressure will be measured at total lung capacity (TLC)
Measured two times: at baseline and after 8 weeks
Snoring intensity
Time Frame: Measured two times: at baseline and after 8 weeks
The participants' bed partners (if applicable) will be asked to rate their partner´s snoring using a Visual Analog Scale (VAS), which ranked the impact of snoring from 0 (no snoring) to 10 (intolerable).
Measured two times: at baseline and after 8 weeks
Tongue base thickness
Time Frame: Measured two times: at baseline and after 8 weeks
This measurement will be performed with a portable ultrasound machine
Measured two times: at baseline and after 8 weeks
Total sagittal thickness
Time Frame: Measured two times: at baseline and after 8 weeks
This measurement will be performed with a portable ultrasound machine
Measured two times: at baseline and after 8 weeks
Lateral pharyngeal wall thickness
Time Frame: Measured two times: at baseline and after 8 weeks
This measurement will be performed with a portable ultrasound machine
Measured two times: at baseline and after 8 weeks
Snoring duration
Time Frame: Measured two times: at baseline and after 8 weeks
This recording will be conducted using the standard microphone application installed on the participant's personal phone and through the use of the free, already validated in studies, SnoreLab application.
Measured two times: at baseline and after 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Université Catholique de Louvain

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 4, 2024

Primary Completion (Estimated)

July 1, 2026

Study Completion (Estimated)

July 1, 2026

Study Registration Dates

First Submitted

October 2, 2024

First Submitted That Met QC Criteria

October 2, 2024

First Posted (Actual)

October 4, 2024

Study Record Updates

Last Update Posted (Actual)

April 29, 2026

Last Update Submitted That Met QC Criteria

April 28, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • RMT-TONGUE

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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