Isometric Handgrip Training Frequency and Blood Pressure in People With Hypertension

NCT06335433 | Recruiting

• 1 other identifier: RM_30_06_22b
• Study Type: interventional
• Target: 45
• Locations: 1 country
• Sites: 1

Brief Summary

Hypertension is the most important cause of cardiovascular disease (CVD), stroke, and premature death (WHO, 2021). It is estimated by The World Health Organisation in 2021 that 1.4 billion individuals across the globe have high blood pressure, with only 14% of people actively managing these elevated levels. Simple and effective lifestyle strategies are required to help people improve their blood pressure and/or attenuate increases in blood pressure with ageing. Physical activity is one possible strategy: in previous research, several different types of physical activity have been shown to have beneficial effects on blood pressure (Blackwell et al., 2017). However, many individuals do not adhere to currently recommended levels of physical activity (150 mins of moderate intensity physical activity per week), due to a combination of the required time commitment, lack of motivation, and the associated levels of effort, exertion, and physical discomfort (Korkiakangas et al 2009). Thus, there is a need to identify alternative exercise interventions which will overcome these barriers but remain effective at improving blood pressure (Herrod, Lund, \& Phillips, 2021, Toohey et al, 2018). Low intensity isometric hand grip exercise training (IET) has been shown to result in large decreases in resting blood pressure in younger and older age groups, in both men and women, and in individuals with normal as well as elevated baseline blood pressure (Badrov et al, 2013; Bentley et al., 2018; Millar et al., 2014). In this research, IET has almost universally involved performing 4 x 2 IET holds at 30% of maximal voluntary contraction, 3 times a week, over a 4-8-week intervention (Millar et al, 2014). There are very few studies that have investigated the effect of changing different protocol parameters on changes in blood pressure and vascular health, and the minimal effective dose of IET is unknown. Defining the minimal effective dose of different types of exercise may help overcome key barriers to exercise by lowering the required time commitment, reducing perceived effort/exertion, and promoting more positive affective responses. One important modifiable parameter is training frequency and it is unknown whether reducing the frequency of IET will reduce the efficacy for improving blood pressure. Therefore, the primary objective of this study is to determine if reducing the frequency of isometric handgrip training from four times a week to two times a week will affect the improvements in resting blood pressure and vascular health in people with hypertension. A secondary objective is to investigate the acute affective and perceptual responses to sessions of IET and the effect of training on these acute affective/perceptual responses.

Conditions

Hypertension

Keywords

High Blood Pressure; Isometric Handgrip Exercise; Vascular Health; Training Frequency; Dose Response; Perceptual Responses

Outcome Measures

Primary Outcomes (1)

• Office measured supine and seated systolic, diastolic and mean arterial pressure

  Office measured supine and seated systolic, diastolic and mean arterial pressure will be measured at baseline and 3 days following the final exercise session

  6 weeks

Secondary Outcomes (7)

• Office measured central systolic, diastolic and mean arterial pressure

  6 weeks

• 24-h mean ambulatory systolic, diastolic, and mean arterial pressure

  6 weeks

• Daytime ambulatory systolic, diastolic, and mean arterial pressure

  6 weeks

• Sleeping ambulatory systolic, diastolic and mean arterial pressure

  6 weeks

• Carotid-Femoral Pulse Wave Velocity

  6 weeks

Study Arms (3)

No Intervention Control

NO INTERVENTION

Participants will be asked to maintain their normal lifestyle patterns (i.e. diet and physical activity) and will undergo no other intervention.

Two Sessions/Week

EXPERIMENTAL

Participants will complete 6-weeks of supervised isometric handgrip exercise training with a frequency of two sessions/week

Other: Exercise Training (Isometric Handgrip Exercise)

Four Sessions/Week

EXPERIMENTAL

Participants will complete 6-weeks of supervised isometric handgrip exercise training with a frequency of four sessions/week

Other: Exercise Training (Isometric Handgrip Exercise)

Interventions

Exercise Training (Isometric Handgrip Exercise) OTHER

Participants allocated to the exercise groups will complete 6 weeks of isometric handgrip exercise training (IHGT) using an electronic hand dynamometer (Camry EH101, Zhongshan Camry Electronic Co. Ltd, Guangdong) for either 2 or 4 sessions per week. Each exercise session will consist of 4 x 2-minute isometric contractions at 30% MVC with 1 minute rest periods between contractions. The first bout will be performed on the dominant arm and then the arm will be alternated for each subsequent two-minute bout. Participants will be instructed to try keep the contraction tension as close as possible to the set tension of 30% MVC using visual feedback from the dynamometer's electronic display.

Four Sessions/Week; Two Sessions/Week

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged between 18 and 65 years.
• Scoring low or moderate on the international physical activity questionnaire (IPAQ).
• Previous diagnosis of high blood pressure and/or a resting systolic blood pressure ≥130 but \<180 mmHg (self-reported and confirmed during screening/baseline assessment).
• Currently taking no anti-hypertensive medicine or taking anti-hypertensive medicine with no treatment change within the last 4 months prior to enrollment.
• Stable dietary and physical activity patterns (including dietary supplementation) over the last 4 months

You may not qualify if:

• Aged \<18 or \>65 years
• Resting blood pressure ≥180/110 mmHg or resting heart rate \>100 bpm during baseline as-sessment
• Manifest cardiovascular disease including cerebrovascular disease, heart failure, chronic kidney disease, peripheral vascular disease, or advanced retinopathy (fundus hypertonicus grades III-IV) based on a self-report health history questionnaire.
• Type 1 diabetes
• History of other chronic disease including malignancy, neurological conditions (e.g. multiple sclerosis) or respiratory conditions (e.g. COPD).
• Contraindications to exercise based on answers to the physical activity readiness questionnaire.
• Physical limitations preventing handgrip exercise (e.g. arthritis or other musculoskeletal disorder)
• Scoring "high" on the international physical activity questionnaire
• Taking more than 2 anti-hypertensive drugs or a change in treatment strategy in the previous 4 months.
• Currently taking nitrate medication (as it is commonly prescribed for angina) or on hormone replacement therapy
• Significant self-reported change in lifestyle patterns in the prior 4 months (e.g. currently on a planned diet for weight loss).

Sponsors & Collaborators

• Swansea University: lead

Study Sites (1)

Swansea University

Swansea, Wales, SA18EN, United Kingdom

RECRUITING

MeSH Terms

Conditions

Hypertension

Interventions

Exercise

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Officials

• Richard Metcalfe, PhD

  Swansea University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Richard Metcalfe, PhD

CONTACT

01792205678; r.s.metcalfe@swansea.ac.uk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Randomised controlled trial

Study Record Dates

• First Submitted: March 21, 2024
• First Posted: March 28, 2024
• Study Start: March 20, 2024
• Primary Completion (Estimated): March 1, 2028
• Study Completion (Estimated): March 1, 2028
• Last Updated: July 6, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)