Inspiratory Muscle Training in Postmenopausal Women

NCT ID: NCT06459674

Last Updated: 2026-02-12

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 28 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-04-12
• Study Completion Date: 2025-09-01

Brief Summary

This study is being conducted by the Department of Kinesiology within the School of Public Health at Indiana University Bloomington. The purpose of this study is to better understand how inspiratory muscle strength training affects cardiovascular health and mood disturbance in postmenopausal women.

Detailed Description

Inspiratory muscle training (IMT) works by strengthening the respiratory muscles through resistive airflow breathing using a handheld device. The goal being to elicit an adaptive response akin to resistance exercise for locomotor muscles. Labored breathing due to respiratory muscle weakness can detract from physical performance with attendant consequences on independent living. This may trigger a maladaptive cycle that worsens physiological and psychosocial outcomes. IMT from 6-10 weeks has been shown to increase maximal inspiratory pressure, functional capacity, and perceived breathlessness across disease states. To inform an appropriately powered randomized controlled trial, the present work proposes a 2-arm single-blind, randomized pilot study to evaluate outcomes of interest.

Conditions

Postmenopausal Symptoms; Aging; Obesity

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

Inspiratory Muscle Training (IMT) group

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 4 times a week, and over 8-weeks.

Group Type: EXPERIMENTAL

PrO2 Fit (IMT Trainer)

Intervention Type: DEVICE

The device is used four times a week over a period of 8 weeks.

Sham Inspiratory Muscle Training (Sham-IMT) group

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 4 times a week, and over 8-weeks.

Group Type: SHAM_COMPARATOR

PrO2 Fit (IMT Trainer)

Intervention Type: DEVICE

The device is used four times a week over a period of 8 weeks.

Interventions

PrO2 Fit (IMT Trainer)

The device is used four times a week over a period of 8 weeks.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Postmenopausal women (self-report at least 6 years since last menstrual cycle)
• Aged 50-75 years (confirmed by birth date listed on participant's driver license at screening visit)
• English-speaking
• Body mass index between 25.0 to 39.9 kg/m2
• Able to ambulate without assistance
• Own or have access to a Bluetooth-capable phone or tablet (IOS version 12.0 or later or Android version 7.0 or later)

Exclusion Criteria

• Unable to provide informed consent.
• Greater than stage II hypertension (i.e., >159/99 mm Hg)
• Current tobacco use (self-report)
• Habitually exercise training ≥ 2 days per week (self-report)
• Significant orthopedic limitations or other contraindications to strenuous exercise
• Live or work > 80 miles from Bloomington, Indiana
• Anticipated elective surgery during the study period.
• Surgery to the chest or abdomen in the last 6 months.
• Plan to move residence or travel out of the local area during the study period.
• History of heart attack or heart condition.
• Current use of prescription medications that affect heart rate or blood vessel dilation (e.g., systemic b-adrenergic blockers, calcium channel blockers, and hormone replacement therapy).
• Diagnosis of asthma or chronic pulmonary disease.
• Current respiratory infection.
• Diagnosis of an aneurysm in the chest, abdomen, or brain.
• Psychological or social characteristics that would interfere with their ability to fully participate in the study.

• Minimum Eligible Age: 50 Years
• Maximum Eligible Age: 75 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: Yes

Sponsors

Indiana University

OTHER

Sponsor Role: lead

Responsible Party

Stephen J. Carter, Ph.D.

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Stephen J Carter, Ph.D

Role: PRINCIPAL_INVESTIGATOR

Indiana University, Bloomington

Locations

Indiana University

Bloomington, Indiana, United States

Countries

United States

Other Identifiers

20387

Identifier Type: -

Identifier Source: org_study_id