Longitudinal Assessment of Maximal Inspiratory Pressure and Functional Capacity Following Inspiratory Muscle Training in Frail Older Adults (IMT-2)

Official title

Longitudinal Assessment of Maximal Inspiratory Pressure and Functional Capacity Following Inspiratory Muscle Training in Frail Older Adults: A Randomized, Double-Blind, Sham-Controlled Trial

Overview

This study aims to evaluate the effects of an 8-week inspiratory muscle training program on maximal inspiratory pressure and functional capacity 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), an established measure of global inspiratory muscle strength. Secondary outcomes include measures of functional capacity, reflecting the ability to perform physical tasks relevant to daily living in very old adults. These outcomes will allow the evaluation of the clinical relevance of improvements in inspiratory 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 inspiratory muscle strength and functional capacity, supporting its potential implementation in rehabilitation and geriatric care.

Interventions

• Device 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.
• Device 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.

Primary outcome measures

• Maximal Inspiratory Pressure (MIP) [Time frame: Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention]
• Six-Minute Walk Test (6MWT) [Time frame: Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention]
• Timed Up and Go Test (TUG) [Time frame: Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention]
• Five Times Sit-to-Stand Test (5STS) [Time frame: Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention]
• Upper Limb Muscle Strength (Handgrip Dynamometry) [Time frame: Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention]
• Lower Limb Muscle Strength (Isometric Knee Extension Dynamometry) [Time frame: Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention]
• Muscle Oxygenation [Time frame: Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention]
• Total Hemoglobin Concentration (THb) [Time frame: Before-intervention; Immediately after intervention; 1-month after intervention; 3 months after intervention]

Eligibility criteria

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

• Acute or unstable cardiovascular, respiratory, or metabolic conditions.
• 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.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Center list to be confirmed — check the primary protocol.

Identifiers

NCT: NCT07328334 · UFV-IMT2

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗