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

21 Participants Needed

Trial Summary

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 data supports the effectiveness of this treatment for high blood pressure?

Blood flow restriction (BFR) exercise, which is part of the treatment, is known to increase muscle strength and size even with low-intensity exercise. Although the specific effect on blood pressure is not directly studied, BFR exercise is considered safe and may offer benefits for special populations, potentially including those with high blood pressure. ^{1 2 3 4 5}

Is Isometric BFR Exercise safe for humans?

Blood Flow Restriction (BFR) exercise can increase muscle strength with low-intensity workouts, but it may cause an exaggerated increase in blood pressure during exercise, which could be risky for people with heart issues. However, it has also been shown to lower blood pressure after exercise in healthy young adults. ^{1 2 4 6 7}

How is the isometric BFR exercise treatment for high blood pressure different from other treatments?

Isometric BFR (blood flow restriction) exercise is unique because it combines low-intensity handgrip exercises with restricted blood flow using bands or cuffs, which may help lower blood pressure without the need for high-intensity workouts. This approach is particularly novel as it offers a non-drug, exercise-based method that could be beneficial for people who cannot engage in traditional high-intensity exercise. ^{1 3 4 5 6}

What is the purpose of this trial?

The goal of this interventional study is to evaluate the acute impact of isometric blood flow restriction (BFR) exercise on blood pressure and other cardiovascular functions in healthy young adult volunteers. The main question it aims to answer is: The investigators hypothesize that isometric BFR exercise with a wide-rigid cuff would lead to greater blood pressure and other cardiovascular responses and that these cardiovascular responses would be greater under isometric BFR exercise with narrow-elastic bands compared with the control condition (no cuff). Participants will perform isometric exercises in 3 laboratory visits with different exercise conditions) no cuff control 2) BFR with wide-rigid cuff 3) BFR with narrow-elastic band.

Eligibility Criteria

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

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

Treatment Details

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.

Participant Groups

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+

Findings from Research

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]

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 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]

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 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]

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]

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]

References

1. Germany pubmed.ncbi.nlm.nih.gov

Knee extension with blood flow restriction: Impact of cuff pressure on hemodynamics. [2020]

2. United States pubmed.ncbi.nlm.nih.gov

Effects of leg blood flow restriction during walking on cardiovascular function. [2022]

3. United States pubmed.ncbi.nlm.nih.gov

Low-intensity isometric handgrip exercise has no transient effect on blood pressure in patients with coronary artery disease. [2022]

4. England pubmed.ncbi.nlm.nih.gov

The effect of acute blood-flow-restricted resistance exercise on postexercise blood pressure. [2011]

5. Germany pubmed.ncbi.nlm.nih.gov

Acute cardiovascular response to unilateral, bilateral, and alternating resistance exercise with blood flow restriction. [2021]

6. Canada 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. [2021]

7. United States pubmed.ncbi.nlm.nih.gov

Influence of Blood Flow Restriction During Low-Intensity Resistance Exercise on the Postexercise Hypotensive Response. [2018]