Isometric Exercise for Hypertension

Effectiveness and Mechanisms of Isometric Resistance Exercise to Reduce Blood Pressure in a Chinese Population: a Pilot Randomized-controlled Trial

Background: Isometric resistance exercises (IREs) have great potential to improve blood pressure (BP) control.

Methods: This is a pilot randomized controlled trial that will involve 50 patients with hypertension (HT) who do not meet the current physical activity guidelines defined by the World Health Organization. Participants will be randomly assigned in a 1:1 ratio using stratified and blocked randomization to either the IRE (wall squat) group or stretching exercise (active control) group. A well-structured, widely accepted, and validated 24-week wall squat program (2 minutes per exercise, 2 minutes of rest between sets, and 3 sessions per week) will be implemented, as it has been commonly used in previous research. All patients will be followed up for 24 weeks. Control group will receive exact same treatment except that IRE is replaced by frequency-matched and time-matched stretching exercise. The primary outcome measure will be rate of recruitment. Secondary outcomes will include BP parameters from 24-hour ambulatory BP monitoring

Study Overview

• Status: Completed
• Conditions: Hypertension
• Intervention / Treatment: Behavioral: wall squat; Behavioral: passive stretching

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • School of public health and primary care

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• a suboptimal daytime SBP of >135-160 mmHg on a 24-h ABPM
• reported no regular physical activity or less than that recommended for adults by the World Health Organization (e.g. <150 minutes of moderate-intensity aerobic exercise per week);
• on stable doses of anti-HT medication(s) for ≥4 weeks if the patient is receiving drug treatments
• agree for no drug changes during the intervention period (24 weeks);

Exclusion Criteria:

• cannot provide informed consent
• unwillingness to repeat ABPM
• relative contraindications to ABPM (i.e. diagnosed atrial fibrillation, nighttime workers, occupational drivers, or patients with bleeding tendencies)
• severe osteoarthritis pending knee replacement surgery
• known secondary HT
• use of ≥3 anti-HT medications at maximum doses or ≥4 anti-HT medications
• SBP or DBP are >160 mmHg or >100 mmHg, respectively, on ABPM
• pregnancy/breastfeeding
• active malignancy

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: isometric exercise; wall squat exercise. Each exercise session will contain 4 sets of 2-minute wall squat isometric holds with 2 minutes of rest between each set (approximately 14 minutes per session in total), and a total of 3 sessions will be arranged every week (with ideally 48 h between exercises)	Behavioral: wall squat; self-learnt wall squat exercise to be conducted for totally 24 weeks
Active Comparator: passive stretching; A frequency-matched (3x/week) and time-matched (~14 minutes each session) passive static stretching exercise will be used	Behavioral: passive stretching; time-matched passive stretching exercise to be conducted for totally 24 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
rate of recruitment	number of people recruited per month	through study completion, an average of 1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure parameters	24-hour, daytime and nighttime blood pressure from 24-hour ambulatory systolic and diastolic blood pressure measurement	24-week after recruitment
Carotid-femoral pulse wave velocity	analysed by applanation tonometry using SphygmoCor (AtCor Medical Pty Ltd) with the accompanying SphygmoCor Software Suite (SphygmoCor System)	24-week after recruitment
flow-mediated velocity (FMD)	FMD will be performed using a high-resolution linear artery transducer couple with a software (FMD suite, Quipu, Italy) that automatically detect and measure the brachial artery diameter and will be performed according to international guidelines	24-week after recruitment

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): July 20, 2024
• Primary Completion (Actual): September 30, 2025
• Study Completion (Actual): November 30, 2025

Study Registration Dates

• First Submitted: July 15, 2024
• First Submitted That Met QC Criteria: July 18, 2024
• First Posted (Actual): July 23, 2024

Study Record Updates

• Last Update Posted (Actual): December 16, 2025
• Last Update Submitted That Met QC Criteria: December 9, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Hypertension; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Physical Therapy Modalities; Patient Care; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Exercise; Muscle Stretching Exercises
• Other Study ID Numbers: IRE001

Plan for Individual participant data (IPD)

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

Drug and device information, study documents

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