Longitudinal Assessment of Lung Function and Respiratory Muscle Strength Following Training of the Inspiratory Muscles in Frail Older Adults (IMT-3)

Longitudinal Assessment of Lung Function and Respiratory Muscle Strength Following Training of the Inspiratory Muscles in Frail Older Adults: A Randomized, Double-Blind, Sham-Controlled Trial

This study aims to evaluate the effects of an 8-week inspiratory muscle training program on lung function and respiratory muscle strength in frail older adults aged 80 years and above. Frailty is associated with reduced physical capacity, declines in functional performance, impaired respiratory performance, and a higher risk of disability. Inspiratory muscle training is a simple, low-cost intervention that may improve breathing function, inspiratory muscle strength, and overall health in very old adults, but evidence in this age group remains limited. Participants will be randomly assigned to one of two groups: a high-load inspiratory muscle training group or a low-load sham training group. Both groups will use a threshold device and perform 30 breaths once per day, five days per week, for eight weeks. The experimental group will train with progressively increasing resistance (50% to 80% of maximal inspiratory pressure), while the sham group will use a minimal and non-progressive load (15% of maximal inspiratory pressure). All sessions will be supervised and monitored for safety. The main goal of the study is to determine whether inspiratory muscle training improves maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP) and lung function. These outcomes will allow the evaluation of the clinical relevance of improvements in respiratory muscle strength in this population.

Assessments will be performed before the intervention, immediately after the 8-week program, and again at one and three months after the end of the intervention to examine both immediate and short-term effects. This study may contribute valuable evidence regarding the safety, feasibility, and clinical benefits of inspiratory muscle training in frail very old adults, particularly its impact on respiratory muscle strength and lung function, supporting its potential implementation in rehabilitation and geriatric care.

Study Overview

• Status: Not yet recruiting
• Conditions: Frailty Syndrome; Respiratory Muscle Weakness; Age-Related Frailty; Geriatric Health
• Intervention / Treatment: Device: Inspiratory Muscle Training; Device: Sham Inspiratory Muscle Training

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Michelle Matos Duarte, PhD; Phone Number: +34 913 24 80 64; Email: michelle.matos@ufv.es

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults aged 80 years or older.
• Clinical diagnosis of frailty, defined by a Short Physical Performance
• Battery (SPPB) score < 9.
• Ability to stand and walk with or without assistive devices.
• Ability to understand and follow instructions for inspiratory muscle training.
• Stable medical condition for at least 3 months prior to enrollment.
• Capacity to provide informed consent or availability of a legal

Exclusion Criteria:

• Severe cognitive impairment that prevents understanding the procedures.
• Diagnosis of neuromuscular diseases affecting respiratory muscles (e.g., ALS, myopathies).
• Severe or uncontrolled hypertension (≥180/110 mmHg).
• Recent thoracic or abdominal surgery (<3 months).
• Severe musculoskeletal disorders limiting participation in training.
• History of recurrent syncope, severe dizziness, or intolerance to respiratory maneuvers.
• Any condition judged by the research team to compromise safety or participation.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Inspiratory Muscle Training; Inspiratory Muscle Training Participants perform an 8-week inspiratory muscle training program using a threshold device (PowerBreathe). Training consists of 30 inspirations, once daily, 5 days per week. The initial load is set at 50% of each participant's maximal inspiratory pressure (MIP) and is increased weekly by 5 cmH#O up to 80% of MIP. All sessions are supervised by healthcare professionals, with continuous monitoring of oxygen saturation and heart rateExperi	Device: Inspiratory Muscle Training; Inspiratory Muscle Training Participants perform 30 breaths once daily, 5 days per week for 8 weeks using a threshold inspiratory muscle training device. The load begins at 50% of maximal inspiratory pressure (MIP) and increases by 5 cmH#O weekly up to 80% of MIP. Sessions are supervised and oxygen saturation and heart rate are monitored.
Sham Comparator: Inspiratory Muscle Training (Sham); Inspiratory Muscle Training (Sham) Participants follow the same 8-week training schedule using the threshold device (PowerBreathe), but with a constant load of 15% of maximal inspiratory pressure (MIP) and no weekly progression. Training consists of 30 inspirations, once daily, 5 days per week. The procedure mimics the experimental intervention but provides minimal physiological stimulus. All sessions are supervised, with monitoring of oxygen saturation and heart rate	Device: Sham Inspiratory Muscle Training; Sham Inspiratory Muscle Training Participants use the same device and schedule as the experimental group (30 breaths once daily, 5 days per week for 8 weeks) but with a constant load of 15% of maximal inspiratory pressure (MIP), with no weekly progression. This mimics the procedure while providing minimal physiological stimulus. Supervision and monitoring are identical to the experimental arm.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximal Inspiratory Pressure (MIP)	Maximal Inspiratory Pressure (MIP) will be measured using a calibrated handheld manometer following standardized respiratory assessment guidelines. Participants will be instructed to perform a maximal inspiratory effort from residual volume through the mouthpiece with their nose occluded. At least three maneuvers will be recorded, ensuring less than 10% variability between attempts. The highest reproducible value (cmH2O) will be used for analysis. This measure reflects global inspiratory muscle strength and is widely validated in older and frail populations.	Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention
Maximal Expiratory Pressure (MEP)	Maximal Expiratory Pressure (MEP) will be measured using a calibrated handheld manometer following standardized respiratory assessment guidelines. Participants will be instructed to perform a maximal expiratory effort from residual volume through the mouthpiece with their nose occluded. At least three maneuvers will be recorded, ensuring less than 10% variability between attempts. The highest reproducible value (cmH2O) will be used for analysis. This measure reflects global inspiratory muscle strength and is widely validated in older and frail populations.	Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention
Forced Vital Capacity	Forced Vital Capacity (FVC) is the maximum volume of air, expressed in milliliters, that the subject is able to inhale during a forced inspiration, which will be measured using spirometry.	Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention
Forced Expiratory Volume in the First Second (FEV1)	Forced Expiratory Volume in the First Second (FEV1) is the maximum volume of air exhaled in the first second, measured in milliliters, which provides information on lung elasticity and will be measured using spirometry.	Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention

Collaborators and Investigators

• Sponsor: Universidad Francisco de Vitoria

Study record dates

Study Major Dates

• Study Start (Estimated): May 20, 2026
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: April 22, 2026
• First Submitted That Met QC Criteria: April 22, 2026
• First Posted (Actual): April 29, 2026

Study Record Updates

• Last Update Posted (Actual): April 30, 2026
• Last Update Submitted That Met QC Criteria: April 29, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Older Adults; Inspiratory Muscle Training; Lung Function; Respiratory Muscle Strength
• Additional Relevant MeSH Terms: Pathologic Processes; Pathological Conditions, Signs and Symptoms; Frailty
• Other Study ID Numbers: UFV-IMT3

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

IPD Plan Description

At this time, it is unclear whether individual participant data (IPD) will be shared.

Data sharing will depend on institutional policies, ethical approvals, participant privacy considerations, and the feasibility of preparing de-identified datasets. A final decision will be made once data collection and analysis are completed.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No