Editor’s Note: Pt. 1, Pt. 2 and Pt. 3 of this four-part article appeared in the April, May and June issues, respectively.
Isometric Exercises and BP Reduction
Isometric resistance training (IRT) is the most effective mode of exercise for reducing both systolic (SBP) and diastolic blood pressure (DBP), and mean arterial pressure (MAP), compared to other forms of exercise like aerobic, dynamic resistance and high-intensity interval training. Isometric training is especially good when your patient is new to fitness.8
The mechanism is that the heart rate decreases a little bit, but cardio output is a stroke volume increase, meaning how much the body's cardio output is going. The change is to total peripheral resistance.
Vessels are a tight tube, and you're pushing blood into them. There's a tightness or stiffness in the arteries from high blood pressure. Something about isometric exercise relaxes that tightness / stiffness, making the vessels more pliable. The magnitude of blood pressure reduction is larger than that observed with dynamic aerobic or resistance training.
The physiological mechanisms of isometric exercise to lower blood pressure:
- Muscle contraction compresses blood vessels, reducing blood flow and temporarily raising blood pressure.
- Upon relaxation, blood surges back, delivering oxygen and nitric oxide.
- Nitric oxide causes blood vessels to widen (enhances vascular dilation), reducing blood pressure.
- Over time, this process decreases arterial stiffness.
- Isometric training also reduces sympathetic nervous system activity, further lowering blood pressure.
The benefits can be a significant reduction in systolic and diastolic blood pressure; improvements in arterial stiffness; enhanced endothelial function; and decreased peripheral vascular resistance.
J.D. Inder’s study8 found average reductions of 6.77 mmHg in SBP and 3.96 mmHg in DBP after isometric training. Another analysis by Edwards, et al., showed even greater reductions of 8.24 mmHg in SBP and 4 mmHg in DBP.9
Isometric exercise may improve basal dilation of blood vessels. It can lead to re-setting of baroreceptors, potentially contributing to long-term blood pressure reduction.
Additional benefits of isometric training include muscle bulk and strength; It may improve bone density and reduce the risk of bone fractures; These exercises can be particularly beneficial for older adults, enhancing mobility and quality of life.10-16
Recommended Isometric Exercise Protocol
- Hold isometric contractions for 20 seconds to 2 minutes at 30-50% of maximum effort.
- Perform exercises four times per day, 3-5 times per week.
- Focus on the same exercise, building up to 2 minutes initially; then vary exercises as you progress.
- Breathe steadily – avoid holding your breath to prevent blood pressure spikes.
Improvements in blood pressure typically manifest after 4-10 weeks of consistent training.
Tucker’s Top Isometrics
If we as a profession taught every patient to do wall sits, planks and static squats (which by the way is obviously helpful for leg strength and healthy aging, pelvic floor and core strength for healthy backs and spines), these isometric exercises could do all that and help reduce blood pressure.
Wall sits with a Swiss ball between the legs. Squeeze the ball and put stress on the muscles without having to go through the full range of motion. Go completely up and down. A good wall squat is when you sit about 90 degrees and hold the position. If you're holding 45 degrees, that's still putting stress on the muscles in your legs.
Edwards, et al., identified wall sits as the most effective individual exercise for reducing systolic blood pressure (-8.24 mmHg), likely due to large muscle group engagement (quadriceps, glutes) and increased vascular response.
Static Squat Hold (without a wall) is a good movement assessment. For someone with mobility issues who can’t do a squat without tweaking a knee or low back, or who can’t do the movement efficiently, isometrics are a great place to start. Then you can move into basically doing the full range of motion.
There is always an easier variation. Think of 90 degrees as being the hardest one. Like wall sits, this targets quads and glutes, offering a portable alternative with comparable effects.
Isometric Push-Up Hold can start with hands on the wall. Just start from there, and eventually go to the counter or chair, then go to the knees on the ground, and then a foot push-up. There's always an easier variation of one of those exercises. The best way is to lower halfway in a push-up position and hold with arms bent. This engages the chest, shoulder, and core, providing a full-body isometric challenge linked to blood pressure reduction.
Planks can be done holding a push-up position with forearms on the ground, keeping the body straight from head to heels. While not specifically isolated in Edwards, et al., planks are a staple isometric exercise engaging the core, shoulders and legs, contributing to overall blood pressure benefits (-8.24/-4 mmHg from isometric training).
Side Planks propped up on one forearm. Lift the hips to form a straight line and hold. This targets the obliques and core, contributing to the systemic effects seen in isometric training.
Isometric Handgrips. Squeeze a handgrip dynamometer or tennis ball at 30% of maximum voluntary contraction for 2 minutes per hand. Inder, et al.,8 noted significant reductions (-6.77/-3.96 mmHg) with handgrip exercises, widely studied for their accessibility and vascular dilation effects. You can stack hand squeezes with almost all the other exercises.
Leg Extension Holds can be performed sitting on a chair or machine. Extend the legs fully and hold the position with quadriceps engaged. Edwards, et al., included leg extensions in their isometric protocols, showing strong blood pressure-lowering effects due to sustained quadriceps contraction.
Glute Bridge Holds, in which the patient lies on their back, knees bent, lift hips to align with shoulders and knees, and holds. This engages the glutes and core, offering a low-impact option with potential blood pressure benefits similar to other isometric holds.
Calf Raise Holds are performed standing only. I like the challenge of rising onto your toes and trying to get all 10 toes to participate. Hold the elevated position without holding on to anything for balance. This activates the calf muscles, which support circulation in the lower body.
Chair Pose Hold (yoga-inspired) is performed standing with the feet together, bent knees, arms raised overhead; and hold as if sitting in an invisible chair. This combines lower-body tension (quads, glutes) with balance, reflecting isometric principles effective for blood pressure.
One of the challenges I like to give to patients is the bench press machine. Instruct the patient to go about halfway to three-quarters press and hold it (goal is up to 2 minutes); they’re going to be able to hold a lot heavier weight than if you were trying to go through the full motions. For example, if the patient is used to performing 100 pounds for 10 reps, I can probably load 120-130 pounds and hold the tension there. It's going to put a different amount of stress on the bones and the muscles. We can teach similar moves for quads, glutes and hamstrings.
References
- Inder JD, Carlson DJ, Dieberg G, et al. Isometric exercise training for blood pressure management: a systematic review and meta-analysis to optimize benefit. Hypertens Res, 2016 Feb;39(2):88-94.
- Edwards JJ, Deenmamode AHP, Griffiths M, et al. Exercise training and resting blood pressure: a large-scale pairwise and network meta-analysis of randomized controlled trials. Br J Sports Med, 2023 Oct;57(20):1317-1326.
- Chrysant SG. Current evidence on the hemodynamic and blood pressure effects of isometric exercise in normotensive and hypertensive persons. J Clin Hypertens, 2010 May 26;12(9):721-726.
- High Blood Pressure (Hypertension). WebMD. Read Here
- Kilbom A, Brundin T. Circulatory effects of isometric muscle contractions, performed separately and in combination with dynamic exercise. Eur J Appl Physiol Occup Physiol, 1976 Dec 6;36(1):7-17.
- “Static Isometric Exercise, Such as Wall Sits, Best for Lowering Blood Pressure.” BMJGroup.com, July 25, 2023. Read Here
- Inder JD, et al., Op Cit.
- “Isometric Exercise vs. Cardio: Which Is Best for Lowering Blood Pressure?” Medical News Today. Read Here
- Hahm M. “Isometric Exercise: Using Body Weight to Lower Blood Pressure.” Mayo Clinic, Jan. 22, 2024. Read Here
