Adapted from my upcoming book, Stress, Science, Spirit: Connecting Out, Up and In to Thrive Under Pressure.

Ever heard of Heart Rate Variability (HRV)? It measures how well synchronized your breathing and heart rate are – but it is also increasingly recognized as an index for how well you are handling physical and emotional stress.

Every time you exhale, your heart slows down a bit. That’s why breathing techniques for relaxation always instruct you to exhale slowly. The more it slows down, the higher your HRV is likely to be and the better you are coping with stress, numerous studies have found. High HRV is good, in other words.

HRV gives a snapshot into the activation level of your vagus nerve, which is the communications superhighway between your brain and your body.

Research shows that people with high HRV – their hearts speed up and slow down more, synchronized to their breathing – are more resilient, physically and emotionally. Since the vagus nerve influences many of our body’s automatic systems, low HRV is associated with a wide variety of issues – emotional struggles, antisocial behavior, inflammatory and cardiovascular diseases, poor fitness and others. People with low HRV are much more likely to die after a heart attack (Robert E. Kleiger, J.Philip Miller, Thomas Bigger Jr., & Arthur J. Moss, 1987; Thayer, Yamamoto, & Brosschot, 2018).

Although our HRV is determined by genetics and your life experiences, you can change it. Early studies of HRV biofeedback has shown promise for helping to heal a variety of illnesses and injuries:

  • Major depression (Karavidas, et al., 2007),
  • Brain injuries (Lagos, Thompson, & Vaschillo, 2013),
  • Cardiac rehabilitation (Climov, et al., 2014),
  • Addictions – including food (Eddie, C. Kim, Deneke, & Bates, 2014; Meule, Freund, Skirde, Vögele, & Kübler, 2012; Penzlin, et al., 2015),
  • PTSD (Reyes, 2014),
  • High blood pressure (Guiping Lin, 2012),
  • Hostility (Lin, et al., 2015),
  • Chronic pain (Melanie E. Berry, et al., 2014).

HRV biofeedback is also showing promise in life-enhancing uses, including:

  • Improving sports performance by reducing anxiety (Paul & Garg, 2016),
  • Preparing military for combat deployment (Lewis, et al., 2015),
  • Grandmothers raising grandchildren (Zauszniewski, Au, & Musil, 2013),
  • Accelerated learning (Harmelink, 2016).

What do all of these have in common? They are interconnected via your “rest and digest” system (the parasympathetic nervous system). Central to it, the vagus (“wandering”) nerve connects the brain, gut (intestines, stomach), heart, liver, pancreas, gallbladder, kidney, ureter, spleen, lungs, fertility organs (in women), voice, ears and tongue.

High HRV indicates that your brain has greater control over the fight-or-flight system, so you are better able – consciously and unconsciously – to turn it down when danger passes.

Imagine that your body is a fire engine speeding down the road “Code 3” – siren screaming and lights flashing. The fire is out and the emergency is over, but you’re not the driver – you are in a back seat repeating to the driver over the intercom, “Slow down, slow down.” The driver will only ease off the gas and hit the brakes when she can hear your instructions.

“You” are your brain, the driver is your flight-or-flight system, the intercom is your vagus nerve and the speed at which your “slow down” messages are actually reaching the driver is your HRV.

If you are saying “slow down” 20 times a minute, but the driver only hears it five times, that’s low HRV. Your brain isn’t well connected to your body. As a result, neither your conscious mind nor your automatic nervous systems have much control, so the fire truck continues to barrel down the road as if there is still a crisis. In contrast, if most of your messages get through, the driver eases off the gas and the wear and tear on your body is reduced.

The usual goal of “stress management” would be to reduce the stressors, which would be like parking the fire engine – stop responding. Avoid “fires.” But how do you do that if it’s your job?

Instead, you can restore balance through activities and attitudes that help make the “intercom” between your brain and body work better, which will show up as increased HRV. Good news: the vagus nerve is two-way communications, so if you improve your HRV, you will help the back-seat driver’s messages get through.

You can improve your HRV directly through biofeedback, breathing exercises and other relaxation techniques. Even more significantly, your HRV will also reflect the strength of your social support, which is crucial to resistance and resilience to stress. A host of other activities will activate your vagus nerve, which has cascading effects that tell the fire engine (the fight-or-flight instinct) to slow down. Researchers have observed that this happens with yoga, meditation, gratitude, prayer, generosity, trusting and trustworthiness, compassion (for yourself and others), hugging a friend and even having a good cry.  These are the “connecting out (to people), in (to yourself and creation, being grounded) and up (values, ethics, spirituality) that Stress, Spirit, Science will describe in stories and practical advice.

Bibliography

Berry, M., Chapple, I. T., Ginsberg, D., Gleichauf, J., & Nagpal, M. (2014). Non-pharmacological Intervention for Chronic Pain in Veterans: A Pilot Study of Heart Rate Variability Biofeedback. Global Advances in Health and Medicine, 3(2), 28–33. http://doi.org/10.7453/gahmj.2013.075

Climov, D., Lysy, C., Berteau, S., Dutrannois, J., Dereppe, H., Brohet, C., & Melin, J. (2014). Biofeedback on heart rate variability in cardiac rehabilitation: practical feasibility and psycho-physiological effects. Acta Cardiologica, 69(3), 299–307. http://europepmc.org/abstract/med/25029875

Eddie, D., Kim, C., Lehrer, P., Deneke, E., & Bates, M. E. (2014). A Pilot Study of Brief Heart Rate Variability Biofeedback to Reduce Craving in Young Adult Men Receiving Inpatient Treatment for Substance Use Disorders. Applied Psychophysiology and Biofeedback, 39(3–4), 181–192. http://doi.org/10.1007/s10484-014-9251-z

Harmelink, A. (2016). Pilot Study of the Effects of Heart Rate Variability Biofeedback on Perceived Stress, Perceived Coping Ability, and Resilience in Accelerated Baccalaureate Nursing Students. Theses and Dissertations. Retrieved from http://openprairie.sdstate.edu/etd/1015

Karavidas, M. K., Lehrer, P. M., Vaschillo, E., Vaschillo, B., Marin, H., Buyske, S., … Hassett, A. (2007). Preliminary Results of an Open Label Study of Heart Rate Variability Biofeedback for the Treatment of Major Depression. Applied Psychophysiology and Biofeedback, 32(1), 19–30. http://doi.org/10.1007/s10484-006-9029-z

Lagos, L., Thompson, J., & Vaschillo, E. (2013). A Preliminary Study: Heart Rate Variability Biofeedback for Treatment of Postconcussion Syndrome. Biofeedback, 41(3), 136–143. http://doi.org/10.5298/1081-5937-41.3.02

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. http://doi.org/10.1111/psyp.12455

Lin, G., Xiang, Q., Fu, X., Wang, S., Wang, S., Chen, S., … Wang, T. (2012). Heart Rate Variability Biofeedback Decreases Blood Pressure in Prehypertensive Subjects by Improving Autonomic Function and Baroreflex. The Journal of Alternative and Complementary Medicine, 18(2), 143–152. http://doi.org/10.1089/acm.2010.0607

Lin, I.-M., Fan, S.-Y., Lu, H.-C., Lin, T.-H., Chu, C.-S., Kuo, H.-F., … Lu, Y.-H. (2015). Randomized controlled trial of heart rate variability biofeedback in cardiac autonomic and hostility among patients with coronary artery disease. Behaviour Research and Therapy, 70, 38–46. http://doi.org/10.1016/j.brat.2015.05.001

Meule, A., Freund, R., Skirde, A. K., Vögele, C., & Kübler, A. (2012). Heart Rate Variability Biofeedback Reduces Food Cravings in High Food Cravers. Applied Psychophysiology and Biofeedback, 37(4), 241–251. http://doi.org/10.1007/s10484-012-9197-y

Paul, M., & Garg, K. (2012). The Effect of Heart Rate Variability Biofeedback on Performance Psychology of Basketball Players. Applied Psychophysiology and Biofeedback, 37(2), 131–144. http://doi.org/10.1007/s10484-012-9185-2

Penzlin, A. I., Siepmann, T., Illigens, B. M.-W., Weidner, K., & Siepmann, M. (2015). Heart rate variability biofeedback in patients with alcohol dependence: a randomized controlled study. Neuropsychiatric Disease and Treatment, 11, 2619–2627. http://doi.org/10.2147/NDT.S84798

Reyes, F. J. (2014). Implementing Heart Rate Variability Biofeedback Groups for Veterans with Posttraumatic Stress Disorder. Biofeedback, 42(4), 137–142. http://doi.org/10.5298/1081-5937-42.4.02

Zauszniewski, J. A., Au, T.-Y., & Musil, C. M. (2013). Heart Rate Variability Biofeedback in Grandmothers Raising Grandchildren: Effects on Stress, Emotions, and Cognitions. Biofeedback, 41(3), 144–149. http://doi.org/10.5298/1081-5937-41.3.06