The Vagus Nerve & Long-exhalation Breathing


This is actually the third time I’ve featured something on the vagus nerve. Overkill, you say? I think not, especially when the vagus nerve is linked to so many different health benefits, including decreasing stress, inflammation, depression and more. AND it can be easily stimulated in a variety of ways that don’t require special equipment or expensive supplements, which makes it a great self-help health “tool.”

This article by Christopher Bergland of The Athlete’s Way delves deeply into the art of using rhythmic breathing, one of the ways mentioned briefly in the Vague About the Vagus? post to positively influence this nerve. By doing a simple process for as little as TWO MINUTES you can help put your body on the road to better health….


Longer Exhalations Are an Easy Way to Hack Your Vagus Nerve

Sebastian Kaulitzki/Shutterstock
Vagus nerve in yellow (source: Sebastian Kaulitzki/Shutterstock)

Respiratory vagus nerve stimulation (rVNS) counteracts fight-or-flight stress.

(by Christopher Bergland) Two years ago, in May of 2017, I published a nine-part series, “The Vagus Nerve Survival Guide to Combat Fight-or-Flight Urges.” The genesis for that series came from a random “Aha!” moment when I noticed a pattern of diverse scientific literature being published by researchers around the world who were correlating unexpected lifestyle factors (e.g., positive social connections (Kok et al., 2013), narrative expressive writing (Bourassa et al., 2017), and self-distancing (Grossman et al., 2016)) with improved heart rate variability (HRV).

This post is a follow-up to, “Diaphragmatic Breathing Exercises and Your Vagus Nerve,” from my nine-part series on combating fight-or-flight physiology. For this post, I’m excited to update what was primarily hypothetical speculation a few years ago with some new scientific literature (Gerritsen & Band, 2018 and De Couck et al., 2019). These studies corroborate that longer exhalations are an easy way to hack the vagus nerve, combat fight-or-flight stress responses, and improve HRV.

You might be asking, “What is HRV?” Heart rate variability represents the healthy fluctuation in beat-to-beat intervals of a human or animal’s heart rate. During the inhalation phase of a breathing cycle, the sympathetic nervous system (SNS) facilitates a brief acceleration of heart rate; during exhalation, the vagus nerve secretes a transmitter substance (ACh) which causes deceleration within beat-to-beat intervals via the parasympathetic nervous system (PNS).

HRV is used to index the robustness of someone’s vagus nerve responses and vagal tone (VT). Higher HRV is associated with stronger vagus nerve function, lower chronic stress levels, better overall health, and improved cognition.

Although much of the clinical research on HRV doesn’t always discuss the vagus nerve, it’s well established that HRV is an effective way to index vagal tone and gauge the robustness of someone’s physiological ability to counteract SNS-driven fight-or-flight stress responses.

Nota bene: I grew up in a household with a neuroscientist father, Richard Bergland (1932-2007), who was also a brain surgeon and author of The Fabric of Mind. My dad idolized Nobel-prize winner Otto Loewi (1873-1961), who discovered the first neurotransmitter (acetylcholine), which is the chief neurotransmitter of the PNS. What we now refer to as acetylcholine or ACh was originally coined “vagusstoff” (German for “vagus substance”) by Loewi around 1921.

In a simple but elegant experiment on frogs (that came to Loewi as a Eureka! moment in a dream), he found that a tranquilizing substance squirted directly out of the vagus nerve onto the heart, which caused a frog’s heart rate to slow down immediately. (See, “How Does “Vagusstoff” (Vagus Nerve Substance) Calm Us Down?“)

 Wikipedia/Creative Commons
Diagram of the frog heart preparation used by Otto Loewi (source: Wikipedia/Creative Commons). Vagus nerve stimulation (VNS) slows heart rate while accelerator (sympathetic nervous system) nerve stimulation speeds up heart rate.

As a tennis player, my father used the same breathing techniques he used in his neurosurgery operating room to stay calm. While coaching my Inner Game of Tennis, dad taught me the basics of how to use deep, slow breathing techniques to hack the vagus nerve and slow down my heart rate, just like a frog in Loewi’s lab.

Dad kept his neuroscience lessons on the tennis court simple. He’d say, “Chris, if you want to maintain grace under pressure, visualize squirting some vagusstoff into your nervous system by taking a deep breath—with a big inhale and a long, slow exhale—as you bounce the ball four times before every serve.”

Without going into too much detail, my father taught me that by increasing the duration of my exhale after taking a deep breath, I could trigger my vagus nerve to squirt out some stress-busting “vagusstoff” on demand. This “stuff” was like a self-made tranquilizer that would relax my nerves and help me avoid choking or double-faulting during match points.

Later in life, when I was a student at Hampshire College, I practiced yoga regularly and was guided by an instructor who also emphasized the importance of focusing on the inhalation/exhalation ratio during yogic breathing exercises. Although he didn’t mention anything to do with neurobiology or psycho-physiology, it was clear that many of the breathing techniques my yoga instructor was teaching emphasized longer exhalations, just like my father had taught me on the tennis court.

Based solely on life experience and insights from my dad, I saw a parallel and had a hunch that these centuries-old methods of shifting the inhalation/exhalation ratio that often had long-winded Sanskrit names such as “bhastrika pranayama” were ancient vagal maneuvers unwittingly designed to hack the vagus nerve long before Otto Loewi discovered vagusstoff.

It’s reassuring to have fresh research corroborate that each of us can trigger a “relaxation response” (Benson et al., 1975) simply by focusing on the inhalation-to-exhalation ratio of our breathing and consciously extending the length of each exhale while doing breathing exercises as we go about our day-to-day lives.

New Research Identifies Multiple Benefits of Longer Exhalations

In 2018, Roderik Gerritsen and Guido Band of Leiden University in the Netherlands published a detailed theoretical review, “Breath of Life: The Respiratory Vagal Stimulation Model of Contemplative Activity,” in the journal Frontiers in Human Neuroscience. This review presents a wide range of studies that illustrate how slower respiration rates and longer exhalations phasically and tonically stimulate the vagus nerve. Using diaphragmatic breathing techniques to kickstart the calming “rest and digest” influence of the parasympathetic nervous system is referred to as respiratory vagus nerve stimulation (rVNS). For more on traditional VNS and non-invasive vagus nerve stimulation (nVNS) see hereherehere, and here.

Throughout their paper, Gerritsen and Band explain how the latest research on rVNS fits into a historical timeline of other techniques used for millennia to harness runaway fight-or-flight stress responses and calm the autonomic nervous system. The authors write:

“The breathing techniques used in contemplative activities (e.g., meditation, yoga, tai chi) include, but are not restricted to, slowing down respiration cycles, shifting to longer exhalations compared to inhalations, shifting the main locus of respiration from the thorax to the abdomen (diaphragmatic breathing), or paying attention to “natural” breathing. Especially slow and deep breathing with emphasis on long exhalation is dominant across traditions, including zen and vipassana—though there are a few practices stimulating faster respiration patterns (i.e., the yoga technique “breath of fire”). The [vagus] nerve, as a proponent of the parasympathetic nervous system (PNS), is the prime candidate in explaining the effects of contemplative practices on health, mental health and cognition.

Frequently adopting these respiration patterns (slowed and with longer exhalations) can explain a significant part of the efficacy found within contemplative activity practice. Though contemplative activities are diverse, they have shown a similar pattern of beneficial effects on health, mental health, and cognition: mostly in stress-related conditions and performance. This pattern can be explained by these controlled breathing exercises.

Clearly, these functions all move the system towards the rest-and-digest mode of operation and away from fight-or-flight. Not only does [the] vagus nerve control heart rate and slow deep breathing; slow respiration rates with extended exhalation could also activate the PNS by vagus nerve afferent function in the airways. This is a form of respiratory biofeedback. Slow breathing techniques with long exhalation will signal a state of relaxation by the vagus nerve, resulting in more VN activity and further relaxation. Though VN involvement can explain the effects on health and mental health, the link with cognition is less clear. One of the links between respiration and cognition is HRV.”

You can read the rest of the article, which includes step-by-step instructions on long exhalation breathing here:

Related Self-help Health posts:

Altruism , Cancer Survival, Better Health And the Vagus Nerve Connection


And here’s something you may want to check out. Every Thursday at 4:15 pm ET cranio-sacral practitioner Ian Watts offers free distance healing sessions. He’s been doing this for years and sees it as a way to deepen his practice, help others and create a happier, healthier world. You can find out more here and here.



p.s. Be sure to subscribe to Self-help Health so you don’t miss any future posts, and tell your friends to do the same. Also check out my website’s To Your Health page and Evolution Made Easier blog for more helpful health tips, tools and information.

Disclaimer: Please note that any information here is provided as a guideline only, and is not meant to substitute for the advice of your physician, nutritionist, trained healthcare practitioner, and/or inner guidance system. Always consult a professional before undertaking any change to your normal health routine.

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