ISOMETRIC EXERCISE AND BLOOD PRESSURE - BEHIND THE HEADLINES
You may have seen the recent headlines claiming that isometric exercises “like wall squats and planks” are best for lowering blood pressure.
Some of you have already asked me about these headlines. Here is a short overview of the study behind it all and my thoughts on the headlines and take home messages.
WHAT IS ISOMETRIC MUSCLE ACTIVATION?
We can define muscle activation as being one of 3 types:
Concentric - the muscle shortens as it works
Eccentric - the muscle lengthens as it works
Isometric - the muscle exerts force without moving
Put simply, in an isometric exercise you are essentially holding a position. There are lots of exercises that involve isometric muscle activation. A common example is a plank.
WHERE DID THE HEADLINES COME FROM?
In July 2023 a study was published in the British Journal of Sports Medicine that investigated the impact of different types of exercise programme on resting blood pressure. This study was a systematic review. This means the authors analysed the results of lots of different trials that had already been performed and published over a period of time (in this case between 1990 - Feb 2023). The study looked at the data from these trials and compared how much participants resting blood pressure dropped after following one of 5 different categories of exercise programme for at least 2 weeks or more:
Aerobic exercise
Resistance training
Combined training (aerobic and resistance)
HIIT (High Intensity Interval Training)
Isometric exercises
The study concluded that isometric exercises were the most effective programme at lowering blood pressure, followed by combined training, resistance training, aerobic exercise and HIIT.
When breaking the exercise forms down further they concluded that isometric wall squats and running were the most effective single exercises at reducing both systolic and diastolic blood pressure (systolic blood pressure is the pressure in your arteries when your heart beats, diastolic is the pressure in your arteries between beats).
CAN PILATES HELP?
A Pilates workout will include concentric, eccentric and isometric muscle activation. After all, Joseph Pilates was all about creating a system of full bodily wellness, so of course he covered everything in his contrology method!
Pilates mat exercises such as the Hundred, Leg Pull Prone and Shoulder Bridge all include isometric muscle activation with bodyweight and gravity providing the resistance. I talk a lot in my classes about the work that should be happening in the parts of the body that are not moving. These parts of the body are still active, providing stability and control…you guessed it, those muscles are working isometrically!
Next time you are on the mat think about exercises such as the Hundred, One Leg Circle, Leg Pull, Side Bend. Think about all those muscles that are working hard to stabilise the body and hold your position.
For clients who specifically want to focus on this area, we can include isometric holds as well as employing other strategies within our programme.
“Above all learn to breathe correctly” (Joseph Pilates).
In a Pilates workout you will be encouraged to breathe through the movement, using the breath as a tool to enhance the exercise. Holding a 60 second plank is all well and good, but if you are straining and holding your breath throughout it all it isn’t likely to do your blood pressure any favours! In a Pilates session you will be encouraged to work with your breath, and to really connect into what your body is doing and feeling. Therefore you will quickly be able to feel whether you are performing an exercise well rather than straining the body in such a way it may be counter productive to managing blood pressure.
LOOKING BEYOND THE HEADLINES
When the study was published in the British Journal of Sports Medicine it quickly generated attention grabbing headlines in mainstream news outlets and magazines. At the time of my writing this blog article the study publication had been picked up by 181 news outlets and Tweeted over 1000 times!
Many of the headlines in mainstream press focussed on the “best” form of exercise. In my opinion this overlooks a significant take home message from the study which is that all of the different categories of exercise were shown to be effective at lowering blood pressure. It is important to remember that some isometric exercises may not be suitable for some people, and this study shows there are lots of different ways you can have a positive effect on blood pressure through exercise.
Interestingly, the specific exercises mentioned in some of the headlines were also a little misleading. One headline from a well known newspaper read “Planks and Wall Sits Best Exercise for Lowering Blood Pressure, Study Says”, whilst another read “Got High Blood Pressure? Why Doing The Plank or ‘Wall Sits’ Might be Better than Going for a Swim”. Both of these headlines specifically refer to planks. Perhaps the journalists chose to mention planks because they are a well known isometric exercise, but planks weren’t specifically mentioned in the study when reviewing individual exercises. A plank is a difficult position to master and hold. Often times a plank can place a lot of pressure on the body, particularly if technique isn’t quite right, and thus it may be counterproductive as part of a blood pressure management strategy.
What about the study itself? How reliable are the findings? Well, one factor that can help us assess how reliable the results of a study may be is the sample size. This means the number of participants or amount of data looked at in a study. In general, a bigger sample size means the results are less likely to have been notably impacted by chance factors. This particular study looked at a good size sample (almost 16,000 participants across 270 studies globally) however because it was a systematic review it is limited by how much the individual studies within the review differed from each other. Variations exist in the criteria and interventions for each trial, and also in the weight of data for each exercise programme type. Current NHS guidelines focus on aerobic exercise so it is perhaps not surprising that a greater number of trials looked at exercises programmes such as cardio, and the number looking at isometric exercise were actually comparatively few. So not perfect, however the findings of this review are certainly interesting and hopefully open the door to more research in this area.
MY CLOSING THOUGHTS
For me the most important thing this study shows is that all forms of exercise studied showed a positive effect on blood pressure. This is great news.
Not every exercise, or form of exercise, is going to be suitable for every person. Furthermore certain activities may be better avoided for those with particularly high blood pressure. When prescribing or recommending an exercise programme we need to consider any other underlying conditions or injuries an individual may have. The efficacy of any exercise programme is going to be significantly impacted by whether that programme is suitable for the individual person physically, and also whether the person is going to be able to stick with the programme. This is much more likely if the exercise is something they enjoy and that makes them feel good. The great news is that this study showed a positive effect of lowering blood pressure with all exercise programmes studied, so do what is most suited to your body and your preference. Movement is medicine!
It is important to remember that there are many different factors that can have an impact on blood pressure such as weight, diet, salt intake, alcohol intake and medication. Exercise is only one element. A blood pressure management plan should take into account all of these factors and not just focus on one element alone. There is no one “quick fix”.
If your blood pressure is high you should consult with your doctor before starting any new exercise programme. They will be able to advise you on the type of exercise that is best suited to you, as well as any other lifestyle and management considerations that may be appropriate. You can find NHS recommendations and guidance here.
References and Recommended Reading:
Exercise Training and Resting Blood Pressure : A large-scale pairwise and network meta-analysis of randomised controlled trials https://bjsm.bmj.com/content/early/2023/08/31/bjsports-2022-106503
Blood Pressure UK: Exercise, Physical Activity and Your Blood Pressure https://www.bloodpressureuk.org/your-blood-pressure/how-to-lower-your-blood-pressure/healthy-living/exercise-physical-activity/
Heart Matters (British Heart Foundation) https://bhf.org.uk/informationsupport/heart-matters-magazine/news/behind-the-headlines/can-planks-lower-blood-pressure
NHS High Blood Pressure (Hypertension) https://www.nhs.uk/conditions/high-blood-pressure-hypertension/