[ What is heart rate variability and why would you want to improve it || How to improve heart rate variability (Light, sleep, diet, hydration, exercise, cold, gratitude, meditation) || Audio visual brainwave entrainment and heart rate variability || Breathing your way to a healthy heart ]
What is heart rate variability and why would you want to improve it
Heart rate variability (HRV) is the term used for the variation in time intervals between heartbeats. It is constantly changing and is controlled by the autonomic nervous system (ANS). The autonomic nervous system has two sides to it.., the sympathetic and the parasympathetic nervous systems.
The sympathetic nervous system is known as the fight or flight response and the parasympathetic nervous system is known as the rest and digest response. In other words, one makes you feel stressed and the other makes you feel relaxed. So already you can see that spending too much time in one could be detrimental to your health.
A low HRV score has been linked among other things to anxiety, depression, stroke, diabetes and heart disease while a high HRV score has been linked to flexibility and resilience along with the reduction of risk to all the negative consequences of a low HRV.
When you are stressed, you will tend to have a low HRV and when you are relaxed you will tend to have a high HRV.
The bottom line is that medically speaking.., HRV is the ability to respond in an instant to changes in environment and is therefore a measure of physiological variability and rhythmic neural control within healthy limits.
A healthy heart rate variability is actually irregular
It seems counter intuitive, but a healthy heart rate variability is actually irregular and not consistent. Otherwise it would be called heart rate consistency right!? HRV is an indication of your hearts ability to change in a very short space of time to suit the situation you find yourself in. HRV regulates digestion, heart rate, blood pressure and breathing. Breathing is in fact one way to improve it and we will get to that later.
As an example of how fast your heart rate can change to suit your physiological state, even the difference between inhaling and exhaling will show significant variation.
When you breathe in you activate your sympathetic nervous system and your heart rate increases slightly. When you breath out you activate your parasympathetic nervous system and your heart rate slows down slightly.
HRV then.., is a relatively easy way to check the functioning and balance of the autonomic nervous system. Historically this is measured by a doctor, but there are now applications and chest strap combinations (not 100% accurate but improving all the time) that can measure HRV.
It’s important to not get too attached to what your HRV is though. Getting stressed about being stressed is not helpful. Rather use the measure itself, or even just the idea of what HRV is, as a motivation tool to do the things that will positively impact your health anyway.
How to improve heart rate variability
So we now know that a good HRV score is worth at least being aware of as it is a fundamental measure of overall health.
What do you do to improve it though if you have found yours to be low or if you are conscious enough of it to want to maximise how healthy you are?
Naturally you should seek medical advice for any imbalance or lack that you discover.
Thankfully, most of the ways to improve your heart rate variability are just good healthy living practices.
And most of these are obvious…
Light exposure and heart rate variability
In modern times we are both lacking in light and starved of darkness.
Lacking in light because we spend so much time inside under artificial light that has a limited range of the various wavelengths of the light spectrum that sunlight does. And starved of darkness because we have extended the hours of light exposure with indoor lighting way past what nature intended and that negatively alters our internal body clock (circadian rhythm).
Sunlight itself will cause various reactions physically and mentally (like vitamin D production), which will effect your HRV and the amount of time spent in the more desirable rest and digest parasympathetic mode.
And research shows that bright light exposure in the evening will actually negatively effect HRV and sleep patterns later that night particularly in the slow wave non REM sleep stages. On the flip-side, bright light in the morning will do the opposite by normalising your circadian rhythm and increasing serotonin production that will actually promote deep sleep that night.
Sleep and heart rate variability
Nothing will more quickly negatively effect your life than not getting enough quality sleep. And heart health is no exception.
Quality sleep will improve every aspect of your life and allow you to handle stressful situations better, cause you to make better choices for diet and exercise (because you will have the energy to do so) and so much more. And all of these choices will effect your HRV.
The part of sleep that is most conducive to improving HRV is non REM sleep. Non REM sleep is the deepest stage of sleep that most healthy people cycle through multiple times per night. Non REM sleep is the part of sleep that usually suffers when people have medical challenges or mental decline with age.
Take the time to get this part of your daily life right. It is the first question most doctors should be asking you if you have a health issue.
Please read the ‘better sleep series’ (link at end of article) for a comprehensive guide of ways to improve the amount and quality of the sleep you get.
Diet and heart rate variability
Research shows a direct correlation between what you eat and the variability of your heart beats. Not surprisingly, fast food tends to result in low HRV while fresh vegetable based foods and foods high in omega 3 fatty acids like fish or flaxseed tend to result in high HRV.
This should be obvious when talking about heart health as it’s been taught to us since we were young that things like saturated fats should be limited compared to fruit and vegetables. Worth mentioning again is that the central nervous system which is linked to HRV controls digestion and that ‘stressing’ this digestive system with too many hard to digest foods will by association lower your HRV.
Hydration and heart rate variability
We all know this again through repetition that drinking enough water is vital for our health. Increasing how much water we drink is one of the most widely prescribed ‘treatments’ for lowering blood pressure, reducing stress and headaches, and maintaining energy.
No convincing needed here I’m sure and no surprise that dehydration (especially after we have put ourselves through physical stress like exercise) will lead to a low HRV score.
Exercise and heart rate variability
Do we even need to talk about this method of improving heart and overall health?
Hopefully by now you are convinced that movement is as important as rest.
It doesn’t have to be anything more than regular walking to get the benefits.
Cold exposure improves heart rate variability
Short term exposure to cold either by water or environment is becoming the in fashion way to improve health thanks to people like Wim Hof (the ice man). The effects of this cold exposure on our body and mind are only just beginning to be understood.
Try blasting yourself with cold water at the end of your shower for a start. It won’t be easy but that is part of the point. If you can get yourself to voluntarily stay in cold water then what else can you get yourself to do?
The first of these two research papers is very interesting in that the study was done by applying cold to the neck of the participants only.., and yet HRV was improved even with just that.
Gratitude improves heart rate variability
Who would have guessed it. Seen by some as all touchy feely (haha) and for mental purposes only.., it seems that even having a gratitude journal can have a positive effect of your HRV.
This study was done with people with an existing level of heart failure showing that gratitude for life isn’t just a nice idea, but could actually extend your life or even save it. Pretty impressive physical result from a simple mental process.
Audio visual brainwave entrainment and heart rate variability
Audio visual entrainment (AVE) and brainwave entrainment (BWE) is the use of an external source of repetitive stimulation like sound, light, vibration or electric current to effect brain activity. This external stimulation synchronises with the patterns of neural activity in your brain.., and then changes them by taking advantage of what is called the frequency following response.
IE: The brain matches the rhythm of the external stimulation, and then follows it as it changes, before then being held in this new position allowing the brain to ‘entrain’ to, and get better at, operating at this new frequency. Deep states of relaxation are often one powerful result although the technology is certainly not limited to this.
It’s important in my opinion to note with AVE or BWE that sometimes the specific frequency used is less important than the practice and overall effect of entraining the brain to be synchronised and relaxed. Certainly some bands of frequency are more effective than others with specific goals though.
The following study shows the use of Alpha (8-12Hz) Brainwave entrainment (in this case auditory) sessions of 20 minutes length and shows a significant improvement in HRV scores.
At the low end of results there was a 16% increase in HRV score while most participants were higher with a score reaching 74% improvement.
SMR brainwave frequencies (12-15Hz) have been shown in other studies to have a similar effect.
Meditation and heart rate variability
This is of course another obvious choice for overall health including improving your heart rate variability score. Anything that helps you relax is likely to positively effect your heart health. Interestingly though, the meditation practices that had the desired positive effect on HRV were the ones that had controlled slow breathing attached to them.
And this leads nicely into the next way of improving your heart rate variability.., breathwork.
Breathing your way to a healthy heart
As I mentioned earlier, even breathing in versus breathing out will effect you HRV. Breathing in increases your heart rate and breathing out reduces it. So right there is an easy way to reduce stress and calm yourself down quickly.
Simply extend how long you breathe out (exhale) for. For example, breathe in for 4 seconds and out for 8 seconds. Do this for even as few as ten breaths and you will notice a significant difference in how you feel.
Of specific use for improving heart rate variability in breathwork practice though is what is called the coherence breath.
The coherence breath and HRV
The coherence breath is a slow continuous pattern of breath that consists of breathing in and out through the nose at a speed of approximately 5 seconds in and 5 seconds out or 6 breaths per minute.
Nasal breathing itself is hugely beneficial to practice and you can learn more about that and other breath practices in the breathwork article on this website (linked at the end of this article).
Again don’t get too hung up on exactly 5 seconds as a number because the actual timing is slightly different depending on your body type. The study below shows actually that the ideal timing is 5.5 seconds in and 5.5 sec out.
I have also seen evidence of it being closer to 6 sec if you are tall and closer to 5 seconds if you are shorter. I use 6 seconds as it feels right to me, so go for either that or 5 as an easy number to use.
As I indicated above, extending the exhale of your breath also has a relaxing effect due to activating the parasympathetic nervous system and this coherence breath does that too. The benefits of slow rhythmic breathing like this can be significant to your health beyond your HRV score.
What’s the overall lesson for improving heart rate variability…
Easy.., good practices known for generations to be good for you are good for you!
I mean that may sound like stating the obvious but sometimes we need to hear the obvious more than once before it becomes obvious for us individually.
Most of us know what to do but sometimes fail to do what we know.
Here’s your chance to change that.