Tag: Heart Rate Variability

Don’t take that bite! Dogs, diets and heart rate variability

Two new reports related to heart rate variability (HRV) reveal more about its significance as a measure of our physical and emotional health. Higher HRV is associated with better stress management. It is a way to peek into the state of a person’s nervous system, particularly the vagus nerve, the mind-body information superhighway. The more active your vagus is, the better you are at coping with stress. It is the neural path through which your “rest and digest” system signals your “fight or flight” system to calm down.

One new article reports that people with high HRV can more easily resist temptation when dieting. Greater self-control of that kind is also linked to better psychosocial and physical health.

HRV is similar in other mammals, so another researcher looked at the relationship between HRV and aggression in dogs, hoping that HRV might predict how aggressive a dog is likely to be. Just as humans with high are better at resisting that extra slice of cake, perhaps dogs with higher HRV would be better able to resist taking a different kind of bite.

The resulting article reports that indeed, less aggressive dogs had higher HRV.  “Dogs with bite histories had significantly lower HRV” and owners who reported that their dogs were aggressive also had lower HRV. The researcher’s work suggested that HRV could be an objective way to measure the effectiveness of dog training that is intended to reduce aggressiveness.

Yoga, one of these days!

I recently met Shannon McQuaide, director of Fireflex Yoga, which leads first responder on-duty yoga classes. Meeting her may finally get me to actually try yoga, even though I have believed for a long time that it would be good for me. In fact, I became absolutely convinced of its benefit when I read Bessel van der Kolk’s book, The Body Keeps the Score

Fireflex Yoga

Fireflex Yoga

He devotes an entire chapter, Learning to Inhabit your Body, to yoga and its benefits.

Van der Kolk describes how he heard about Heart Rate Variability (HRV, a big topic of Stress, Science, Spirit) as a measure of how well your brain and body are connected.  Activities that increase your HRV will help quiet the fight-or-flight instinct that is responsible for the negative health consequences of carrying too much stress too long. Remember that, as I wrote in You cannot starve the evil wolf, escaping or avoiding stress usually backfires. You have to “feed the good wolf” through attitudes and activities – anything that increases your HRV will accomplish that. Yoga is a powerful way to “feed the good wolf,” in part because of its emphasis on breathing techniques. HRV essentially measures how well synchronized your heart and breathing are.

Van der Kolk’s research showed that traumatized people, including marines at Camp Lejeune, indicate that yoga is effective for helping people with ordinary or highly traumatic stress heal and grow.

I will admit that I’m a lot like “Annie,” van der Kolk’s patient who said, “I don’t know all of the reasons that yoga terrifies me so much, but I do know that it will be an incredible source of healing for me and that is why I am working on myself to try it.

After the earthquake

After the earthquake

Yoga is about looking inward instead of outward and listening to my body, and a lot of my survival has been geared around never doing those things.” I’m not quite “terrified,” but whenever I think about trying something like yoga, part of me seems to resist, strongly.


In 1990, I passed up an opportunity to try yoga in post-earthquake Haiti. I was with a Jordan International Aid medical relief team, traveling in and around Port-au-Prince putting on clinics. It was an overwhelming task – every day, far more people were lined up for care than we could possibly see. Women and children were especially hard hit- poor sanitation always hits them harder.

JIA Yoga

JIA medical team doing yoga in Port-au-Prince, Haiti.

Most evenings when we returned to the house where we operated from, some of the medical team would lead a yoga session. Even our Haitian national policemen were joining in, but somehow I just couldn’t bring myself to try it. I can’t claim to know why we sometimes are so resistant to things that we know would be good for us. I do know that it is related to stress and trauma. Shannon has invited me to join one of her classes at a fire station. Somehow, that seems safer than going to a classroom of strangers whose life experiences are unlikely to resemble mine. It seems to be important to start journeys of healing with people who understand, at a level beyond words, where we are coming from.

How Well Connected are Your Brain and Body?

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.


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