In the world of mind-body medicine, a key modality that can help you to achieve greater awareness of your mind and body is biofeedback. As the name implies, this is a method in which you are given feedback about what is happening in your body in response to your mind (certain thought patterns, states of relaxation/intention, etc.). If you have ever tried to meditate, you may have encountered some frustration and/or curiosity about whether you are doing it correctly and thus if it is really making a difference on your mind and/or body? Biofeedback can provide such information simply. To evaluate the health of your heart and nervous system, you just need a heart rate variability monitor (typically it uses a sensor with an app). This allows you to do biofeedback at home or on the go with your smartphone and a small sensor that plugs into your phone. A key biofeedback technique that has gained considerable popularity is Heart Rate Variability (HRV).
What is Heart Rate Variability (HRV)?
Heart Rate Variability is the measure of the variation in time between each heart beat. When there is increased variability between heart beats, this is referred to as high HRV and when there is less variability between heart beats, it is known as low HRV. HRV is regulated by the nervous system (more on this shortly) and is measured via electrocardiogram classically, but now more frequently with a HRV monitor. A healthy heart is one that has a heart rate that is able to fluctuate with changes in the nervous and endocrine (hormonal system) as well as a number of other regulatory systems in the body.
Heart rate variability has gained considerable attention in research and practice as it is considered an important indicator of psychological resiliency (or the ability to handle stress). This has implications for both mental and physical health. Decreased heart rate variability has been shown to be a strong and independent predictor of future health problems. Moreover, decreased HRV can exacerbate inflammation, high blood pressure, and a number of chronic diseases and is correlated with increased all-cause mortality. Decreased heart rate variability is an independent predictor of future cardiac events and mortality, cardiac-related sudden death from heart attacks and fatal arrhythmias.
Why does HRV affect disease risk?
The heart’s nervous system: The heart has an extensive nervous system that permits it to respond to cues from the emotions and the body. This response often precedes the brain’s response to such stimuli and the heart’s nervous system can override the brain’s nervous system! The HeartMath research group states the the heart is an organizing force throughout the body (as evidenced by synchronization of electrocardiogram (ECG or EKG) and electroencephalogram (EEG) waves, depicting the rhythms of the heart and nervous system, respectively).
The body’s nervous system: Now to the primer on the nervous system (as promised). Our nervous system is known as the ‘Autonomic Nervous System’ or ‘ANS’ and is comprised of two branches: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system (SNS) is the branch that helps us to respond to fight-or-flight situations and helps us to mitigate acute stressors. The parasympathetic nervous system (PNS) governs the relaxation response and controls a number of functions in our body automatically (digestion, breathing, sleeping). The parasympathetic nervous system is predominant when we are quiet, focused, or at rest. It is also active in the arousal and erectile phases of love-making.
Nervous sytem imbalances and HRV: When the two branches of the nervous system (SNS & PNS) are imbalanced (such as in states of chronic or excessive stress with increased cortisol and catecholamine output), the heart’s electrical system can become disrupted, leading to decreased heart rate variability and an increased risk of a number of pathological changes of the heart (see below for more on this). Some have described the imbalance as having one foot on the accelerator in a car and the other on the gas (i.e. the sympathetic nervous system is the gas and the parasympathetic nervous system is the brake). The more pressure on the gas pedal (i.e. stressors), the harder the brake needs to be applied. Such is the case with the nervous system that increased stressors overtax the parasympathetic nervous system as it tries to counterbalance the drive of the sympathetic nervous system. The end result in your body is lowered HRV.
Who uses HRV?
Heart Rate Variability has classically been used by cardiologists, but now enjoys wider use by athletes, the military and by law enforcement, as well as health conscious individuals seeking to optimize health and performance. Athletes use HRV to monitor for overtraining (which is associated with a decreased HRV) and in the military it is used to assess for combat readiness, in stress inoculation protocols and for posttraumatic stress disorder.
Factors that improve HRV include:
- Diet (Green leafy vegetables, Omega-3 polyunsaturated oils (fish oils) and a Mediterranean-style diet, wine? (when paired with Omega-3 fatty acids, wine shows some benefits to HRV).)
- Exercise (moderate exercise). Excessive exercise (overtraining) can decrease HRV
- Herbs (such as St. John’s Wort)
- Supplements (such as GABA)
- Medications (select antidepressants, antihypertensive and cardiac medications)
- Cognitive Behavioral Therapy (CBT)
- Mind-body therapies (gratitude, prayer, chanting mantras, listening to classical music and/or meditations, biofeedback, controlled breathing, focusing on a positive emotion)
- Expressive writing
- Hydrotherapy? (Cold temperatures acutely raise HRV and thus I theorize that alternating hot and cold applications as performed with hydrotherapy or a sauna followed by immersion in cold water may have a beneficial impact on HRV)
Factors that decrease HRV include:
- Shift work (You can read more about how to minimize the health risks of shift work here.)
- Overtraining (excessive exercise)
- Tobacco smoke
- Chronic illness
HRV and health risks:
A number of mental health disorders are associated with decreased HRV:
- Social Isolation
- Posttraumatic stress disorder (PTSD)
- Suppressed anger
and a number of physical health conditions are associated with decreased HRV:
- Irritable Bowel Syndrome (IBS)
- Insulin resistance
- Metabolic syndrome
- Hot flashes
- Neurological disorders
- Restless Leg Syndrome
- Rheumatoid Arthitis
- Atopic dermatitis
HRV and health benefits
Improvements in HRV are associated with decreased perception of pain, lowered inflammation, improved recovery from surgery, decreased risks of heart disease and mortality in addition to increased resiliency against stress.
What are some ways to increase your HRV?
In addition to the factors listed above that can improve HRV, states of appreciation, gratitude, caring for another person or pursuit are associated with improved HRV. A number of mind-body techniques can help to improve your HRV (referred to as achieving ‘coherence’ (a state in which the heart and mind are aligned)). Here are a couple that you can try:
HeartMath’s Quick Coherence Technique:
- Focus your attention in the area of your heart
- Imagine that your breath is flowing in and out of your chest area, breathing a little more slowly or deeply than usual
- Inhale for a count of 5 seconds
- Exhale for a count of 5 seconds
- Attempt to experience a regenerative feeling (appreciation or gratitude for a person or thing in your life)
Prolonged Exhalation Breathing Exercise
- Place the tip of your tongue just behind your upper front teeth and keep it there throughout the exercise.
- Exhale completely through your mouth with some force to produce a sound of air leaving the mouth/blowing out
- Close your mouth and inhale quietly for a count of 4 seconds
- Then hold your breath for a count of 7 seconds
- Finally exhale completely through your mouth (again produce a sound) for 8 seconds
This is one breath. Repeat the cycle a minimum of 3 times, or more as needed/desired.
Where can I find a device to measure my HRV?
There are a number of heart rate variability monitors available to consumers. Here are some of the more commonly used devices (that you can use with the appropriate app and sensor):
Patients in my practice and those on my mailing list can receive a 10% discount and free shipping on Heart Rate Variability monitoring equipment through HeartMath. If you would like to be added to my mailing list to receive this discount, please sign up here and contact the clinic with a request for the discount information to be sent to you.
In case you are on the fence about the rationale and importance of increasing your HRV, consider this:
Increasing HRV can increase will-power and self-control and thus make it easier to put your health goals into action. Furthermore, people who were able to increase their HRV were better able to tune out distractions, delay gratification and manage stressful situations than those who were not able to improve their HRV.
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DeWitte, N.A.J., Buyck, I., & Can Daele, T. (2019). Combining Biofeedback with Stress Management Interventions: A Systematic Review of Physiological and Psychological Effects. Applied Psychophysiology and Biofeedback. DOI: 10.1007/s10484-018-09427-7
HeartMath Institute. (n.d.). Scientific Foundation of The HeartMath System [Video file]. Retrieved from https://www.heartmath.org/resources/videos/scientific-foundation-of-the-heartmath-system/
Jimenez-Morgan, S., & Molina Mora, J.A.(2017). Effect of Heart Rate Variability Biofeedback on Sports Performance, a Systematic Review. Applied Psychophysiology and Biofeedback, 42(3), 235-245.
Lewis, G.F., Hourani, L., Tueller, S., Kizakevich, P., Bryant, S., Weimer B., & Strange, L. (2015). Relaxation training assisted by heart rate variability biofeedback: Implication for a military predeployment stress inoculation protocol. Psychophysiology, 52(9), 1167-1174.
McCraty, R. (n.d.). Heart Rate Variability (HRV) Basics. Retrieved from https://www.naturopathicce.com/course/hrv-basics/
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Utzinger, M. L. (2018). Enhancing Heart Rate Variability. In D. Rakel (Ed.), Integrative Medicine. (4th ed.). (pp. 922-929). Philadelphia, PA: Elsevier.