Traditionally, scientists assumed that our hearts acted like a kind of metronome: that the heart always kept a regular, strict rhythm and only started to beat faster under the influence of exertion or stress. Heart rate variability (HRV), they had never heard of it at the time.
Science has now recognized that this short-sighted theory is far from the truth. Not only has much more accurate equipment shown otherwise, but insights have also changed significantly over the years. For example, scientists and doctors assumed that varying intervals between heartbeats were an indication of an increased risk of heart disease.
Nowadays, they’ve come to realize that it’s exactly this natural variation, even if it’s only a matter of milliseconds, that can provide precious insights, and above all, benefits for our health, both emotionally and physically. This naturally varying heartbeat-to-heartbeat interval is called heart rate variability (HRV).
What is Heart Rate Variability?
Heart rate variability is the varying interval between heartbeats. This interval from heartbeat to heartbeat is constantly changing. Even though it’s only a matter of milliseconds, there is always a slight difference.
The illustration below shows the heart rate variability between three heartbeats on an electrocardiogram (ECG). You can immediately see that the interval between the heartbeats constantly varies, even if only a fraction. While scientists previously thought these different intervals indicated an increased risk of heart disease, researchers at the HeartMath Institute have concluded that this indicates an (emotionally / physically) solid and resilient heart.
The variability of the heart rate is a result of a synergistic action between the two parts of our autonomic nervous system. To interpret this result, we need to have some knowledge of the functioning of the nervous system.
The nervous system concerning HRV
The sympathetic nervous system is the part of the autonomic nervous system that controls and triggers the organs to act to fulfill their function. The parasympathetic nervous system does the exact opposite and calms the organs to recover after this activity. Both parts of the nervous system constantly interact and anticipate each other and the living environment.
Both parts of the nervous system also influence heart function. The sympathetic nervous system speeds up the heartbeat while the parasympathetic nervous system slows it down after action. Both the sympathetic and parasympathetic nervous systems work together constantly to keep cardiovascular activity functioning optimally so that the heart can always respond to environmental factors.
Just picture it. When we still lived in harsh and primitive conditions, the body had to constantly adapt. The hunt required great physical effort. In these stressful situations, effort and rest are constantly alternated. It’s not surprising that a large heart rate variability is an indicator of remarkable heart function resilience. The greater the heart variability, the stronger and more resilient the heart is.
You can guess the consequence because this is exactly the reason why long-term stress is so bad for your health. When hardly any more cortisol – an anti-inflammatory hormone – is produced, the inflammation sensitivity increases enormously. Often there is only low-grade inflammation initially, but in the long term, it can develop into disease and eventually cancer.
And although we can measure most physical issues, equipment development to measure the psychological problems is relatively speaking only in its infancy. But, to measure is to know, and the pioneers of HeartMath Institute are well on their way!
Heart rate variability and our nervous system
Heart rate variability is the interval between different heartbeats. While in the past, scientists assumed that this interval as a metronome was always the same. Today, heart specialists know that there is a variation in time between each heartbeat.
A primitive part of the autonomic nervous system controls this variation. It works regardless of our thinking mind and regulates our heart rate, blood pressure, respiration, and digestion, among other things.
This autonomic nervous system is divided into two parts: the sympathetic and parasympathetic nervous system, also known as the fight or flight mechanism (accelerator pedal), and the relaxation response (brake pedal).
The brain is constantly processing information in the hypothalamus. The hypothalamus sends signals to the rest of the body via the autonomic nervous system to stimulate or relax the various body functions.
In this way, our nervous system is busy all day long processing all kinds of stimuli and maintaining a balance, also called homeostasis. However, when we experience persistent stress, sleep poorly, eat unhealthily or experience loneliness, this balance becomes disturbed (think of the accelerator pedal), and the system becomes overstrained. We have a hard time dealing with stressful situations, and we can interpret this stress from the heart rhythm variability.
Heart rate variability and heart complaints
Heart rate variability is exciting and easy to measure way of identifying imbalances in our nervous system. Once the nervous system is in a fight or flight mode, the variation between successive heartbeats is low. In a more relaxed state, the variation between the heartbeats increases again.
In other words, the more balanced your nervous system is, the better you are able to deal with changing circumstances. In recent decades, research has shown a link between low HRV and stress.(1) Low HRV is even associated with an increased risk of death and cardiovascular disease.(2)
Heart Rate Variability chart
By measuring your HRV, you get personal feedback about your lifestyle and your emotional resilience. This knowledge can help to improve your lifestyle, eat healthier and sleep better. It can also indicate that you have to learn to deal with stressful situations differently from a more cognitive perspective.
It is fascinating to see how the HRV changes in a positive way as you apply attention, meditation, sleep, and especially physical activity in your life. For those who like statistics, this can be a fun and exciting way to keep track of how the nervous system reacts to the environment and your own emotions, thoughts, and feelings.
How do you measure your heart rate variability?
You can measure the heart rhythm variability using an electrocardiogram (ECG), but it is easier to measure it with the Inner Balance Trainer or emWave2 from HeartMath Institute. These devices are easy to carry with you throughout the day, unlike an ECG machine.
Heart rate variability on your Apple Watch
If you have an Apple Watch, you can measure your heart rate variability (HRV). You will need an Apple Watch Series 1 or newer.
The Apple Watch’s HRV functionality is a welcome addition to the countless health functions that the watch already has. When exercising, you can see at a glance whether you are in the right heart rate zone, and additionally, the heart rate variability (HRV) offers you insight into how far you can deal with stress factors.
Measuring the HRV is very easy with the Apple Watch. The watch measures the functioning of your body’s autonomic nervous system – the system that controls body processes without you having to do anything consciously.
In addition to the automatic function, you can manually take an HRV measurement by doing a session with the Breathing app.
1. Sit in a quiet place.
2. Open the Breathing app and press Start.
3. Run the session as indicated on the screen. Make sure you sit relaxed while doing this.
4. Open the Health app, and on the Data tab (with the four colored boxes), tap the Heart item.
5. Tap Heart Rate Variability
6. View the measurements by day, week, month, or year.
Train your HRV
We can train heart rate variability and thus stress resilience. It all has to do with heart coherence. Below are a few tips to improve your heart coherence and your HRV.
Positive emotions: Take a few moments a day to evoke positive emotions. Just a few minutes at a time are enough to experience pleasant feelings and thus feel peace in your system.
Breathing exercises: your breathing, heartbeat, and emotions are directly connected and in constant interaction. Slowing down your breathing and deepening it will slow your heart rate. Calm, deep breathing has a positive effect on your autonomic nervous system. By deliberately slowing down and deepening your breathing several times a day, you reduce stress, increase the HRV value, and your body is better able to deal with stress.
HRV Biofeedback Training
Biofeedback is a treatment method in which body signals are measured with sensors and where you receive feedback about these signals. Based on the results about, for example, muscle tension, the way of breathing, the heart rate, skin temperature, and conductivity, a specialist can determine what the physical condition is. The same applies to HRV (heart rate variability), a good indicator of your emotional state.
Biofeedback training can be an excellent treatment for both mental and physical complaints and stress without medication use. You will find answers to questions such as what is heart rate variability, what is heart coherence, and how can biofeedback with heart coherence provide health benefits?
What is Heart Rate Variability?
Previously, doctors and scientists believed that each heartbeat’s time interval was the same and indicated a healthy heart. Today it has been recognized that this time interval differs from heartbeat to heartbeat.
This difference in the interval indicates a healthy and resilient heart, the researchers at the HeartMath Institute found. Not only does a higher heart rate variability indicate a healthy heart, but it also appears to indicate a significantly more resilient emotional state. Conversely, a heart that beats like a metronome is dangerously unhealthy in many cases.
There are, of course, many factors that influence the heart’s response. Just imagine: a moment when you are frightened, your breathing stops, and in reaction, your muscles tense. Our emotions constantly influence our heart rate variability.
Heart rate variability (HRV) is an indicator of how variable or changeable the heart rate is. The HRV summarizes several different measures.
HRV as a marker in biofeedback training
Heart rate variability values correlate with a series of significant health parameters, including the risk of various (heart) diseases and even total mortality and performance indicators. It is a positive indicator as the HRV has more variability. Large heart rate variability does not necessarily guarantee good health but is certainly a good indicator.
It is essential not to use HRV as a single marker. It is always important to use multiple biofeedback methods to get a complete picture of the emotional and physical state.
What is Heart Coherence?
Heart coherence or heart rate coherence is a particular pattern of heart rate variability in which the heart rate changes in sync with breathing. Here, the variability accelerates when inhaling and slows down when exhaling.
Of course, we know that breathing and heart rate interact. When we exert ourselves, both breathing and heart rate accelerate. When we relax again, the breathing and heart rate slow down again. In a state of heart coherence, the effect is maximal with a particular breath, around six breaths per minute.
The phenomenon of heart coherence is entirely natural and is based on bodily reflexes. However, factors that disrupt this rhythm are destructive emotions such as fear, anger, and frustration.
HRV Biofeedback training
With HRV biofeedback, it is possible to train heart coherence. Two important factors achieve a state of heart coherence:
1. Breathing: breath in slowly and steadily, but also naturally, freely, and relaxed. Ideally, this is about six breaths per minute, but if you need more breaths, that’s also fine. The challenge for yourself is to determine an ideal frequency.
2. Focus on positive emotions, such as gratitude, appreciation, and love.
When you practice both of these factors, you will quickly achieve results with biofeedback training. Breathing is the most significant influence and brings peace to the “system,” positive emotions can be seen as the catalyst.
How does biofeedback training work for stress or anxiety?
In a state of stress or anxiety, there is incoherence. In other words, breathing and heartbeat do not work well together. To gain a better understanding of this, let’s take a closer look at the underlying physiology.
The autonomic nervous consists of two parts: the sympathetic nervous system, which triggers action and thus acts as the accelerator, and the parasympathetic nervous system, which acts as a brake, restores relaxation.
The parasympathetic nervous system causes the heart rate to slow down on exhalation. When inhaling, the parasympathetic influence is blocked, and the heart rate accelerates again.
During stress and anxiety, the parasympathetic nervous system is hardly active, and the heart rate remains high. The stress will considerably accelerate the associated breathing (these always work together). Just think of high chest breathing and hyperventilation under stressful conditions.
When training heart coherence, you exercise the parasympathetic nervous system. You can see it as fitness for the brain, where you influence your breathing with the rational mind and thereby evoke positive emotions.
Biofeedback training for heart coherence
HRV Biofeedback training for heart coherence is an excellent way of therapy to live a more relaxed, healthier, and happier life. For this form of biofeedback training, it is not even necessary to see a therapist.
The HeartMath Institute has developed handy biofeedback equipment that you can easily take with you and carry with you all day long. These devices measure in real-time how your heart coherence is so you can train it by evoking positive emotions with your conscious mind and choosing the right way of breathing. You can order the HeartMath Institute equipment through their website.
Energetic fields and HRV synchronization in adults and groups
Anyone who has ever attended a championship or a festival where a DJ “plays” the audience will recognize that something “energetic” took place there. This is a typical example of a moment where the artist is in sync with his audience. They seem to communicate as if in a state of flow on an invisible energetic level.
We see it as a “good atmosphere” or “team spirit,” but this is, in fact, the energy exchange between the team members, the audience and the artist, and the festival guests.
In an unexplained way until recently, the physiological activity between individual individuals appears to be energetically synchronized. The exchange of energies merges into a larger whole as in a whirlwind and brings the participants energetically to a great height. Several studies suggest that an energetic field directly connects individual group members and at the same time spreads information between the group members.
These biologically generated magnetic fields can act as a carrier wave for transferred information between individuals and group members.(1) The beating heart produces a magnetic field. This field radiates externally from the body and transfers information to locations outside the body. Many people report that they can ‘feel’ the presence of this energy, as well as the emotional state, regardless of body language or other factors.(2,3)
A striking study that also points to an information field connecting group members was conducted during a firewalking ceremony that looked at synchronized heart rhythms between fire walkers and spectators.(4)
A study examining HRV synchronization and coherence levels in 10 groups, each with four individuals, showed that those in an HRV coherent state helped others to transition to a more coherent state.(5)
Measuring HRV can be a great tool for many people to create awareness about their health and how they live and think. It is a good indicator of how your behavior affects the nervous system and body functions.
While knowing your HRV itself will not help you avoid stress, it can help you understand how to respond to stress in a better way and live a happier, healthier life. By measuring the HRV as a preventive tool, you get insights into the most primitive part of your brain. So you see: measuring is knowing!