Heart Rate Variability and Your Resilience

By Shannon Thompson

Decades of psychological research suggests that resilience is a key determinant of success in life. You most likely believe that’s true—or else you wouldn’t be reading a blog like this. But how do psychologists know this sort of thing? How are they able to pinpoint what “resilience” looks like in the first place? This blog will focus on the different ways that resilience can be measured, and how you can use this type of data to build resilience in your own life.

Psychology is often called a “soft” science. The term “soft” refers to the murkiness of the conclusions that can be drawn from data often subjectively reported by humans (“hard” science would refer to findings drawn from objective, measurable data). A great deal of psychology research is conducted using questionnaires involving Likert scales. Findings are established based upon patterns observed within these responses. As you can imagine, data gathered from people’s subjective experience is far less concrete than values that can be objectively measured. In psychology research there is often no oxygen level, or precise exerted force, or concentration of substance to quantify. There is only human reflection. This subjective, often personally nuanced human feedback is what comprises the “softness” within the science of psychology.

Yet, there are some physiological measures that can be used to reflect aspects of psychological experience. One of these is heart rate variability (HRV). Heart rate variability is just as it sounds – the degree to which the timing between a person’s heartbeats varies. The following article will explain the measurement of heart rate variability, why this is a useful measure to be aware of, and the implications of the levels of this measure. It turns out that heart rate variability is the most accurate measure of your overall stress, and has found to be related to cardiovascular disease and mental health (these findings are drawn from “hard” science). It is also a strong predictor of psychological resilience. Heart rate variability is also malleable through adjustments of sleep, diet, and exercise, and the utilization of stress management strategies.  

What is Heart Rate Variability?

As mentioned above, heart rate variability is the varying degree of time between your heart beats. The heart rate is controlled by the autonomic nervous system (ANS). This system operates unconsciously, and controls other bodily functions like our breathing, digestion, and blood pressure. The ANS is comprised of two main systems: the sympathetic nervous system (which is responsible for activating the stress response), and the parasympathetic nervous system (which is responsible for deactivating the stress response). Both the sympathetic and parasympathetic nervous system receive instructions from the hypothalamus, another structure within the brain. Each system is engaged according to the demands of a person’s life. Sleep quality, interpersonal interactions, emotions, and nutrition all impact the stress system, and the subsequent activity of both the sympathetic and parasympathetic nervous system. Someone experiencing a great deal of stress is likely to have a low HRV due to the constant activation of the sympathetic nervous system. Picture an elastic band that is always being stretched, there is not a lot of room for movement. Conversely, a more relaxed person is likely to have a higher HRV due to the dynamic interplay between both the sympathetic and parasympathetic nervous systems. Picture an elastic band at rest, which is able to stretch and relax with applied pressures.   High heart rate variability is desirable, while a low heart rate variability is less ideal. 

What Are the Benefits of Having High Heart Rate Variability?

Heart rate variability has been established as the most accurate measure of overall stress. HRV levels are reflective of the degree by which a person’s parasympathetic nervous system (relaxation response) is active. High HRV within an individual indicates that a person’s parasympathetic nervous system is healthy, strong and responsive. Low HRV levels indicate a chronically activated sympathetic nervous system (stress response), and an underactive, ineffective relaxation response. Researchers have found that people with high HRV tend to be more psychologically resilient than those with a low HRV. Also, high HRV individuals often experience less anxiety, depression, and cardiovascular disease. For athletes, HRV can also be a useful measure for tracking proximity to over-training. 

How Do You Measure Your Heart Rate Variability?

The most accurate way to measure your heart rate variability is with the help of your doctor. The test is brief, non-invasive, and painless. However, there are some easier ways to measure HRV on your own. Some phone apps sync with heart rate monitors like Polar and Garmin, and work with these devices to provide HRV measures. Probably the least accurate, but easiest method of all are phone apps that measure HRV without a heart rate monitor, like Welltory.

In a meta-analysis of HRV research, physiologists Sawane and Gupta advise monitoring your HRV as a weekly average. Their findings indicate that average HRV fluctuations by week are a better indication of your overall HRV than fluctuations by day. For athletes in heavy training who want to use HRV to prevent overexertion, Sawane and Gupta advise tracking of both the HRV and the resting heart rate. Decreases in HRV alongside a resting heart rate that also drops or remains constant is not typically a cause for concern. However, decreases in HRV witnessed in conjunction with an increase is resting heart rate can be indicative of over-training, and could suggest a rest may be in order.

The Psychology Of It All 

How Can You Improve Your Heart Rate Variability?

This is where psychology comes in. Up until this point our discussion has focused on physiology. Now, we turn to psychology, and its relationship with HRV. As touched on above, numerous factors impact a person’s HRV. The quality of a person’s diet and sleep play a role. Regular exercise also has been shown to improve HRV in those whose activity level could be considered sedentary to recreational (increased exercise does not normally improve HRV in high level athletes). The key to improving HRV, cardiologist Steven Sinatra explains is improving your “parasympathetic tone.” Parasympathetic tone is essentially the activity and strength of the relaxation system in your body. When you have a strong parasympathetic tone, your heart rate is held at a low, healthy rate (around 70 bpm), and your blood vessels dilate. Activities performed regularly that activate the parasympathetic nervous system strengthen the parasympathetic tone over time. 

“Essentially, you train your heart through regular practice to have a conversation with your mind, and ultimately alleviate stress,” Cardiologist, Stephen C. Sinatra explains. “Over time, you can learn to generate a relaxation response that calms and balances the ANS. Focus mostly on physical activities that involve conscious breathing, such as Tai chi, yoga, Pilates, relaxation, meditation, and imagery sessions – and do these several times a week.” 

It appears that focused breathing in particular is the key to strengthening parasympathetic tone. In one study, researchers subjected participants to either a twelve-week swimming program, or a twelve-week yoga practice. Upon completion of the study, only the group that practiced yoga had improved their HRV.

Dr. Sinatra elaborates: “The researchers did not speculate as to why [the yogi’s HRV improved, but the cyclist’s did not], but I feel that it had to do with the breathing, and its relaxing effect on the autonomic nervous system, that is so important in yoga. When you are in a yoga twist or stretch – especially if it’s uncomfortable – breathing through it will ease discomfort, while also improving HRV.”

Dr. Sinatra’s theory is supported by science. The practice of yogic pranayama breathing (also known as belly breathing, activates the vagus nerve, which is the primary control mechanism of the parasympathetic system. When the vagus nerve is activated, the parasympathetic system is engaged. Frequent activation of the vagus nerve improves parasympathetic tone (also known as vagal tone). 

Therefore, one of the simplest methods to improve your HRV (and your resilience) may be to practice belly breathing. To do so, place your hand on your belly. Let your stomach relax, so that it protrudes, like it might if you had eaten too much. Breathe in slowly, by first expanding your belly. Allow the air to travel up through your rib cage and into your lungs. Then, exhale by allowing the air out of your lungs, and back down through your soft belly. Any belly-breathing you do can be beneficial (some is always better than none). But, if you can belly-breathe for six minutes, while keeping your attention on the breath, you will also gain the benefits of mindfulness, another excellent focus and stress reduction exercise.

Grounding For Heart Rate Variability:

Grounding is a mindfulness method that involves making contact with the earth. Types include walking outdoors barefoot, digging your feet in the sand, or simply standing in grass. Dr. Sinatra explains, “you see the earth has a natural energetic field. When you have physical contact with the Earth’s surface, you absorb the natural healing energy of our planet.”  Dr. Sinatra and colleagues have found through research that regular grounding can help improve HRV. He recommends grounding 150 minutes each week. Other methods to improve HRV that Dr. Sinatra recommends include avoiding exposure to electronics, pollutants, and toxins. He also advises regular counseling for anyone struggling with mental health challenges such as anxiety and depression.

In my role as a mental performance consultant, I’ve developed an interest in heart rate variability regarding its potential use with my clients. I’m curious if monitoring their HRV could provide early cues that a meditation or relaxation exercise might be useful. Perhaps by utilizing this measure we could catch burnout or over-training before it becomes severe. My considerations have included personal experimentation with HRV. I’m currently measuring my HRV each morning. In fact, just two days ago I spent about twelve hours highly alarmed about a situation in my life. When I measured my HRV during that time it was notably lower than normal. Now, a few days and a great deal of breathing later, my HRV has returned to its prior healthy level.  This simple measurement of the heart is helping me to have a better gauge as to the health, and resilience of my mind.

About the Author 

Shannon Thompson is a mental performance consultant who specializes in high performance sport. Shannon holds a Master of Applied Positive Psychology degree from the University of Pennsylvania.