Isometric BFR Exercise for High Blood Pressure

Overseen By Lin-Sheng Chen, MS

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Texas at Austin

Disqualifiers: Hypertension, Diabetes, Obesity, Stroke, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

Duration: 3 visits

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines how a specific type of exercise affects blood pressure and heart health. Participants will perform handgrip exercises three times, using different equipment each time: once without any special bands, once with a wide band, and once with a narrow band. Researchers aim to determine if the bands influence blood pressure changes during exercise. Healthy young adults without high blood pressure or other listed health issues may be suitable for this trial. As an unphased trial, it offers participants the chance to contribute to new insights in exercise and cardiovascular health.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. However, since the study involves healthy young adults without certain medical conditions, it's possible that participants should not be on medications for those excluded conditions.

What prior data suggests that isometric BFR exercise is safe for cardiovascular health?

Research has shown that isometric handgrip exercises, even with added blood flow restriction (BFR), are generally safe. One study with 21 men who had heart disease found low-intensity isometric handgrip exercise to be safe. This exercise builds muscle strength and reduces tiredness without the injury risks associated with heavy workouts.

When using a wide, stiff cuff for BFR, some studies suggest it might cause a temporary rise in blood pressure and a feeling of increased effort or slight discomfort. However, these effects are short-lived and usually not harmful. Overall, both the narrow, stretchy band and wide, stiff cuff methods appear safe for exercise. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about these treatments for high blood pressure because they explore a novel, non-drug approach using isometric exercises combined with blood flow restriction (BFR) techniques. Traditional treatments often involve medications like ACE inhibitors or beta-blockers, but these exercises offer a drug-free alternative that could reduce side effects and improve patient adherence. The use of a narrow-elastic band or a wide-rigid cuff during handgrip exercises is being tested to see if it enhances the blood pressure-lowering effects by uniquely restricting blood flow, which might optimize muscle engagement and cardiovascular benefits. This approach could offer a new, accessible, and cost-effective way to manage high blood pressure.

What evidence suggests that this trial's treatments could be effective for high blood pressure?

Research suggests that squeezing a handgrip can help lower blood pressure. This trial will compare different methods of isometric handgrip exercises. Participants in one group will use a narrow elastic band during exercises, which studies have shown increases heart and blood vessel responses more than without it. Another group will use a wide, firm band, which has been found to have manageable side effects and effectively control high blood pressure. Both methods show promise in naturally managing blood pressure. ^{1 4 5 6 7}

Are You a Good Fit for This Trial?

This trial is for healthy young adults aged 18-40 who are interested in how different types of isometric handgrip exercises affect blood pressure and cardiovascular health. They must consent to participate.

Exclusion Criteria

Arterial calcification

Abnormal clotting times

Acid-base imbalance/acidosis

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Participants perform isometric exercises in 3 laboratory visits with different exercise conditions: no cuff control, BFR with wide-rigid cuff, and BFR with narrow-elastic band.

3 visits

3 visits (in-person)

Follow-up

Participants are monitored for blood pressure and cardiovascular responses before, during, and after exercise.

20 minutes

What Are the Treatments Tested in This Trial?

Interventions

• Isometric handgrip exercise with a narrow-elastic band
• Isometric handgrip exercise with a wide-rigid cuff

Trial Overview The study tests the effects of three conditions on cardiovascular responses: regular handgrip exercise, handgrip with a wide-rigid cuff (BFR), and handgrip with a narrow-elastic band (BFR). Each participant will try all three methods across separate lab visits.

How Is the Trial Designed?

Group I: Isometric exercise with wide-rigid BFR cuff Experimental Treatment 1 Intervention

Group II: Isometric exercise with narrow-elastic BFR band Experimental Treatment 1 Intervention

Group III: Isometric exercise without BFR cuff (control) Active Control 1 Intervention

Who Is Running the Clinical Trial?

University of Texas at Austin

Lead Sponsor

Trials

387

Recruited

86,100+

Published Research Related to This Trial

In a study involving ten young, healthy men, postexercise hypotension (PEH) was observed only after high-intensity (HI) resistance exercise, indicating that this type of exercise is more effective for lowering blood pressure compared to low-intensity blood-flow-restricted (BFR) exercise.

The research suggests that while BFR exercise is a low-intensity alternative, it may not provide the same blood pressure-lowering benefits as traditional high-intensity workouts, which could be important for populations looking to manage blood pressure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of acute blood-flow-restricted resistance exercise on postexercise blood pressure. Rossow, LM., Fahs, CA., Sherk, VD., et al.[2011]

In a study of 17 healthy young volunteers, exercise with blood flow restriction (BFR) significantly increased heart rate and blood pressure while decreasing stroke volume, indicating a higher cardiac workload during low-intensity exercise.

The findings suggest that BFR can impair endothelial function, as shown by decreased vasodilation, which raises concerns about its safety for individuals with compromised cardiac conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of leg blood flow restriction during walking on cardiovascular function. Renzi, CP., Tanaka, H., Sugawara, J.[2022]

In a study involving 20 healthy participants, alternating (ALT) blood flow restriction (BFR) exercise resulted in significantly higher cardiovascular responses, including greater increases in aortic and mean arterial blood pressures compared to unilateral (UNI) and bilateral (BIL) patterns.

For individuals concerned about cardiovascular strain, unilateral or bilateral BFR exercises may be safer options than alternating patterns, as they produced lower cardiovascular responses during the exercise.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Acute cardiovascular response to unilateral, bilateral, and alternating resistance exercise with blood flow restriction. Stanford, DM., Park, J., Jones, R., et al.[2021]

In a study involving 21 male patients with coronary artery disease (CAD), low-intensity isometric handgrip exercise was found to be safe for participants.

Despite its safety, the isometric handgrip exercise did not result in a temporary reduction in blood pressure, indicating it may not be effective as a nonpharmacologic tool for lowering BP in CAD patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low-intensity isometric handgrip exercise has no transient effect on blood pressure in patients with coronary artery disease. Goessler, K., Buys, R., Cornelissen, VA.[2022]

Low-intensity resistance exercise combined with blood flow restriction (BFR) can lead to significant decreases in systolic and diastolic blood pressure after exercise, indicating a beneficial postexercise hypotensive response.

In a study involving 15 young men, both high-intensity exercise and low-intensity exercise with BFR resulted in similar blood pressure responses, suggesting that BFR can be an effective alternative for achieving cardiovascular benefits with less strain.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influence of Blood Flow Restriction During Low-Intensity Resistance Exercise on the Postexercise Hypotensive Response. Maior, AS., Simão, R., Martins, MS., et al.[2018]

In a study involving 11 healthy male participants, blood flow restriction (BFR) during knee extension exercises showed that higher cuff pressures (60%, 80%, and 100% of arterial occlusion pressure) significantly reduced absolute blood flow compared to no restriction, with reductions of 34% to 72%.

Despite the reductions in absolute blood flow, BFR exercises still elicited a hyperemic response, indicating that BFR can effectively stimulate muscle activity even at high cuff pressures, although tissue oxygenation decreased with increased pressure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Knee extension with blood flow restriction: Impact of cuff pressure on hemodynamics. Singer, TJ., Stavres, J., Elmer, SJ., et al.[2020]

The blood flow restriction (BFR) technique during arm-curl exercises significantly intensifies the blood pressure response, raising concerns about potential cardiovascular risks.

This intensified blood pressure response is linked to the muscle metaboreflex triggered by postexercise muscle ischemia in the elbow flexors, suggesting that BFR may require careful monitoring during exercise.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Exaggerated pressor response to blood flow restriction resistance exercise is associated with a muscle metaboreflex-induced increase in blood pressure in young, healthy humans. Hori, A., Hasegawa, D., Suijo, K., et al.[2021]

Citations

1. withpower.com withpower.com/trial/phase-blood-pressures-8-2024-becac

Isometric BFR Exercise for High Blood Pressure In a study involving 20 healthy participants, alternating (ALT) blood flow restriction (BFR) exercise resulted in significantly higher cardiovascular responses ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4225874/

Effect of Isometric Handgrip Exercise Training on Resting ... Result: There was a significant reduction in resting blood pressure following 10 wk of exercise training. Both Systolic and Diastolic blood pressure reduced ...

3. researchgate.net researchgate.net/publication/385981830_The_Effect_of_Isometric_Handgrip_Training_With_and_Without_Blood_Flow_Restriction_on_Changes_in_Resting_Blood_Pressure

The Effect of Isometric Handgrip Training With and Without ... Isometric handgrip (IHG) training lowers resting blood pressure (BP) in both hypertensives and normotensives, yet the effect of training dose on the magnitude ...

4. clinicaltrials.gov clinicaltrials.gov/study/NCT04448236

Effect of Blood Flow Restriction Resistance Exercises in ... The objective of this study is to investigate the additional effects of 2-week BFR-RE in patients with COPDAE on top of the conventional in-patient ...

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7727422/

EFFECT OF BLOOD FLOW RESTRICTION TRAINING ON ... The purpose of this study was to examine muscular performance, pain and vascular function in response to eight weeks of BFR compared to traditional resistance ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC3721942/

Effect of short-term isometric handgrip training on blood ... The findings suggest that 15 minutes of sitting per day for five consecutive days is just as effective as isometric handgrip training for reducing BP levels.

7. sciencedirect.com sciencedirect.com/science/article/pii/S1440244025004724

Blood flow restriction training improves strength, fatigue ... The results showed significant improvements in perceived disease impact, muscle strength, fatigue, physical activity levels, and manual ...