Blood Pressure Following Isometric Exercise in Inactive Adults

Not Applicable

Recruiting

• Conditions: Hypertension; Elevated Blood Pressure; Sedentary Lifestlye

• Registration Number: NCT06937164
• Lead Sponsor: Canterbury Christ Church University

Brief Summary

This study investigates how isometric exercise training (IET) affects blood pressure in physically inactive adults. Isometric exercise involves sustained muscle contractions without movement-for example, pushing against a fixed object. Previous research has shown that IET may help reduce blood pressure, but the mechanisms involved are not fully understood.

The purpose of this study is to assess both the immediate (acute) and long-term (chronic) effects of IET on cardiovascular outcomes. Participants will complete a series of lab-based exercise sessions over several weeks. In these sessions, they will perform repeated bouts of isometric leg extensions while seated on an exercise machine designed to measure muscle force.

Throughout the study, researchers will monitor participants' blood pressure, heart rate, and muscle activity. Acute responses-such as post-exercise hypotension (a short-term drop in blood pressure)-will be measured immediately after exercise. Chronic changes, such as resting blood pressure improvements, will be evaluated across the training period.

Additional measurements will include heart rate variability (HRV), which gives insight into autonomic nervous system activity, and electromyography (EMG), which tracks muscle fatigue and activation patterns. These data will help explore potential mechanisms behind the cardiovascular benefits of IET.

By examining how repeated sessions of isometric exercise influence blood pressure and related physiological responses, this research may support the use of IET as a non-pharmacological strategy for managing or preventing hypertension in physically inactive individuals.

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-04
• Study First Submitted: 2025-04-07
• Study First Submitted QC: 2025-04-17
• Study Start: 2025-04-21
• Study First Posted: 2025-04-22
• Last Update Submitted: 2025-05-15
• Last Update Posted: 2025-05-16
• Primary Completion: 2025-08-30
• Study Completion: 2025-09

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 36

Inclusion Criteria

• Age 18 years or older
• Self-reported physically inactive or insufficiently active (not meeting current physical activity guidelines)
• Not currently engaged in structured resistance or isometric exercise training
• Able to attend lab sessions over a 4-week period
• Provides written informed consent

Exclusion Criteria

• Current diagnosis of hypertension requiring medication
• Any known cardiovascular, neurological, or musculoskeletal condition contraindicating isometric exercise
• Formal education or professional background in exercise science, physiology, or a related field
• Pregnant or planning to become pregnant during the study period
• Inability to follow verbal instructions or complete study protocols

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Change in Resting Systolic Blood Pressure	Baseline to Post-Intervention (approximately 4 weeks)	Systolic blood pressure will be measured at rest using a Task Force Monitor prior to and after the isometric exercise intervention period. The primary outcome is the change in resting systolic blood pressure from baseline to final testing. Measurements are taken in a seated position following standard resting protocols.

Secondary Outcome Measures

Name	Time	Method
Change in Muscle Fatigue Markers (EMG)	Baseline to Post-Intervention (Approximately 4 weeks)	Muscle fatigue will be assessed using surface electromyography (EMG) of the vastus lateralis. Fatigue indices include changes in median frequency and torque stability over repeated contractions.
Change in Diastolic Blood Pressure	Baseline to Post-Intervention (approximately 4 weeks)	Diastolic blood pressure will be assessed in the same manner as systolic. The secondary outcome is the change in diastolic values from baseline to final testing.
Post-Exercise Hypotension Response	During the first week of the exercise intervention. Sessions 1, 2 and 3.	Post-exercise hypotension will be evaluated as the change in systolic and diastolic blood pressure immediately following each isometric exercise session, compared to pre-exercise baseline.
Change in Heart Rate Variability (HRV)	Baseline to Post-Intervention (approximately 4 weeks)	HRV will be analyzed using Task Force Monitor data to assess autonomic modulation. Measures include time-domain (e.g., RMSSD) and frequency-domain (e.g., LF/HF ratio) indices.

Trial Locations

Locations (1)

Canterbury Christ Church University; 🇬🇧 Canterbury, Kent, United Kingdom