Feasibility and Effects of Inspiratory Muscle Training Combined With Blood Flow Restriction for Frail Older Adults

Feasibility and Effects of Inspiratory Muscle Training Combined With Blood Flow Restriction for Frail Older Adults: A Pilot Randomized Controlled Trial

This randomized controlled trial study aims to evaluate the feasibility and preliminary efficacy of a combined inspiratory muscle training (IMT) and blood flow restriction (BFR) intervention in frail older adults. Outcomes of interest include feasibility, physical function, respiratory muscle strength, handgrip strength, five-times sit-to-stand performance, body composition, frailty level, fall efficacy, blood pressure, and adverse events.

Study Overview

• Status: Not yet recruiting
• Conditions: Older Adults; Frailty Syndrome; Inspiratory Muscle Training; Blood Flow Restriction (BFR) Training Effects
• Intervention / Treatment: Behavioral: Exercise; Behavioral: Sham Control

Detailed Description

This is a parallel randomized controlled trial. 30 participants who are older adults with frailty will be enrolled.

Eligible participants who complete the baseline measurements will be randomly allocated to a combined BFR and IMT intervention group (N=15) or in the control group with BFR and sham IMT (N=15).

Primary outcomes include feasibility and physical function (i.e., the Short Physical Performance Battery (SPPB), 6-minute walk test (6MWT), and Time Up and Go (TUG) test). Secondary outcomes include respiratory muscle strength, handgrip strength, five-times sit-to-stand performance, body composition, frailty level, fall efficacy, blood pressure, and adverse events. All outcomes will be assessed at baseline (T0) and immediately after the 6-week intervention period (T1) in both groups.

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

Contacts and Locations

• Study Contact: Name: Pei-Shan Tsai Professor, PhD; Phone Number: 6321 +886227361661; Email: ptsai@tmu.edu.tw

Study Locations

• Taiwan
  • Taipei, Taiwan, 11031
    • Taipei Medical University
    • Contact: Pei-Shan Tsai Professor, PhD; Phone Number: 6321 +886227361661; Email: ptsai@tmu.edu.tw

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Community-dwelling adults aged 65 years and older who are classified as at least "vulnerable" using the Clinical Frailty Scale (score ≥4).
• Participants must have no cognitive impairment and be able to follow commands, as assessed by the Mini-Mental State Examination (MMSE).

Exclusion Criteria:

• (1) are unable to participate in exercise (e.g., due to severe musculoskeletal disorders)
• (2) have high-risk factors for exercise, such as uncontrolled hypertension (>150 mmHg systolic blood pressure (SBP) / >90 mmHg diastolic blood pressure (DBP), coagulation disorders, and deep venous thrombosis
• (3) have hematological disorders or are using hematology related-medications
• (4) have significant comorbidities, including a history of stroke, diabetes with severe complications, or cardiovascular diseases
• (5) chronic lung conditions (e.g., obstructive pulmonary disease, asthma), and
• (6) have participated in a structured exercise training program within the past 3 months at a frequency exceeding three sessions per week.

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: Intervention group; Participants in the experimental group will receive a 6 week combined BFR and IMT intervention	Behavioral: Exercise; Each session will last approximately 60 minutes and will include three components: (1) an initial 3-minute IMT exercise performed at an intensity corresponding to rating of perceived exertion (RPE) 11-13 on the Borg 6-20 scale, (2) a 50-minute low-intensity exercise program combined with BFR, and (3) a second 3-minute IMT session at the same target intensity. For the IMT, the protocol follows a progressive intensity model, starting with 30% of the maximum inspiratory pressure (MIP) in Week 1 to allow participants to become familiar with the technique. The intensity will gradually increase to a target of 60% MIP by Week 6, based on the participants' tolerance. For the BFR, during weeks 1-2, participants will train at constant loads. From weeks 2-6, training loads will be increased. Cuff pressure will be prescribed relative to the calculated arterial occlusion pressure (AOP): 50% in weeks 1-2, 60% in weeks 3-4, and 70% in weeks 5-6 for both lower- and upper-body exercises.
Sham Comparator: Control group; Participants in the control group will receive a 6-week combined combined BFR and sham IMT intervention.	Behavioral: Sham Control; Participants in the control group will perform the identical BFR exercise protocol as the intervention group. However, IMT will be delivered at 2% of MIP, which is considered a sham condition and has not been shown to improve respiratory muscle function

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recruitment rate	The recruitment rate will be calculated by dividing the number of recruited participants by the number of eligible participants	T0 = baseline; T1 = immediately after intervention
Attrition rate	Attrition rate is the proportion of randomized participants who withdraw from the study or are lost to follow-up before completing the final assessment.	T0 = baseline; T1 = immediately after intervention
Exercise Enjoyment	Enjoyment will be assessed using a single-item Exercise Enjoyment Scale, which asks participants, "How much did you enjoy the exercise session?). Responses are rated on a 7 Likert scale ranging from 1 (not at all) to 7 (extremely)	T0 = baseline; T1 = immediately after intervention
Short Physical Performance Battery (SPPB)	The SPPB consists of three components-standing balance, gait speed, and repeated chair stands-each scored from 0 to 4 and summed to a total score ranging from 0 (worst performance) to 12 (best performance). Lower SPPB scores indicate poorer physical function and a higher risk of adverse outcomes, with scores below 10 predictive of all-cause mortality in older adults.	T0 = baseline; T1 = immediately after intervention
6-Minute Walk Test (6MWT)	The 6MWT will be used to assess functional exercise capacity. Participants will be instructed to walk as far as possible along a flat, straight course for 6 minutes, and the total distance is recorded.	T0 = baseline; T1 = immediately after intervention
Time Up to Go (TUG)	The TUG test is used to assess functional mobility, balance, and fall risk in older adults, incorporating a series of dynamic activities. Participants will be instructed to rise from a chair, walk three meters at a comfortable pace, turn around, walk back to the chair, and sit down. The total time taken to complete the task is recorded, with longer times indicating poorer functional mobility and higher fall risk	T0 = baseline; T1 = immediately after intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Respiratory Muscle Strength	We will use the S-Index Test to evaluate the respiratory muscle function based on maximum dynamic inspiratory pressure, which is a recommended tool developed by POWERbreathe. Participants will be advised to avoid strenuous exercise for 24h and to rest in a sitting position for 15 minutes before the assessment. Then, they performed eight inspiratory maneuvers in a standing position, divided into three to four series of two to three repetitions.	T0 = baseline; T1 = immediately after intervention
Handgrip Strength	Handgrip strength will be evaluated to estimate the maximum upper-limb muscle function in older adults. Participants will be seated with the shoulder adducted, the elbow flexed to 90°, and the forearm and wrist in a neutral position. They will then be instructed to squeeze the dynamometer as forcefully as possible.	T0 = baseline; T1 = immediately after intervention
Five-times sit-to-stand	The five-times sit-to-stand test is simple to administer and has been widely applied in both clinical and research settings. Participants will sit with their backs against the chair and be instructed to stand and sit five times as quickly as possible.	T0 = baseline; T1 = immediately after intervention
Frailty level	The Clinical Frailty Scale (CFS) is a 9-point global clinical measure ranging from 1 (very fit) to 9 (terminally ill), used to classify frailty severity in older adults. A traditional Chinese version of the CFS has been validated in Taiwanese older adults, demonstrating acceptable inter-rater reliability and good criterion validity against established frailty measures	T0 = baseline; T1 = immediately after intervention
Fall Efficacy	The short form of the Falls Efficacy Scale-International (FES-I) includes 7 items rated on a 4-point Likert scale from 1 (not at all concerned) to 4 (very concerned). The total score ranges from 7 to 28, with higher values indicating greater concern about falling	T0 = baseline; T1 = immediately after intervention
Adverse events	The study team will record adverse events during the intervention caused by the exercise, including falls, fractures, exercise-related pain, dizziness, muscle strain, sprains, respiratory and cardiac adverse events, and hospitalization.	T0 = baseline; T1 = immediately after intervention
Fat mass	Fat mass will be assessed using a body composition analyzer and recorded in kilograms	T0 = baseline; T1 = immediately after intervention
Fat-free mass	Fat-free mass will be assessed using a body composition analyzer and recorded in kilograms.	T0 = baseline; T1 = immediately after intervention

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Borg Rating of Perceived Exertion (RPE) Scale	The Borg RPE scale reflects an individual's subjective perception of exercise intensity, integrating sensations of physical effort, breathlessness, and fatigue. The scale ranges from 6 to 20, where 6 indicates "no exertion at all" and 20 indicates "maximal exertion." This RPE score will be assessed every training session	T0 = baseline; T1 = immediately after intervention
Automated Office Blood Pressure	Automated Office Blood Pressure will be monitored before and after intervention to minimize cardiovascular risks and ensure that timely medical assistance is available for participants who experience any discomfort. Upon arrival at the lab, participants will be asked to sit for at least 5 minutes before the first blood pressure reading; the average of two readings will be used for that visit	T0 = baseline; T1 = immediately after intervention

Collaborators and Investigators

• Sponsor: Taipei Medical University
• Collaborators: National Taiwan University; The University of Texas at Austin

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): October 1, 2026

Study Registration Dates

• First Submitted: April 23, 2026
• First Submitted That Met QC Criteria: May 1, 2026
• First Posted (Actual): May 7, 2026

Study Record Updates

• Last Update Posted (Actual): May 7, 2026
• Last Update Submitted That Met QC Criteria: May 1, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: older adults; frailty; inspiratory muscle training; blood flow restriction
• Additional Relevant MeSH Terms: Pathologic Processes; Pathological Conditions, Signs and Symptoms; Frailty; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Exercise
• Other Study ID Numbers: 2025-UAAT-UTS02

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