Ever heard of the vagus nerve? From its association with stress, mental health and wellness, to heart rate variability and respiratory sinus arrhythmia (and a related term called vagal tone), this nerve certainly seems to play an important role in our lives. For those of you newer to the vagus nerve, here are some interesting facts – it is a cranial nerve (number 10 of 12 cranial nerves, in fact), that originates in the brain (specifically the medulla), and the name “vagus” can be translated as “wandering.” It is called the wandering nerve because it influences the function of multiple organs (heart, lungs and digestive tract to name a few) and it is the longest nerve of the autonomic nervous system in the body. The vagus nerve is a primary component of the parasympathetic branch (“rest and digest”) of our autonomic nervous system, as opposed to the sympathetic branch (“fight or flight”). Specifically, research suggests that stimulating the vagus nerve activates the parasympathetic branch of the nervous system; a “vagal brake” if you will.  

Interestingly, the wandering vagus nerve runs behind the throat, suggesting that we can gently stimulate the vagus nerve when we do things like singing, chanting and yes, breathing -particularly deep breathing (Kromenacker et al., 2018). In fact, there is research to suggest that we can stimulate these inhibitory responses to our nervous system through our breath (Senthilnathan et al., 2019). You might be wondering how to measure vagus nerve activation.  Well, earlier in this piece, I mentioned the term vagal tone, which is defined as vagus nerve activity. It has become quite popular as a novel way to measure stress vulnerability and can be measured in various ways. The most common non-invasive way is through heart rate and heart rate variability or measuring the variability in the time interval between heartbeats. Increased vagal tone (and thus vagal action) is generally associated with a lower heart rate and increased heart rate variability. And guess what else?    

High heart rate variability is also associated with better emotion regulation, decision-making and attention (Thayer & Lane, 2009). The role of the vagus nerve in calming the body through parasympathetic nervous system activation is clear. While we don’t have much control over most of our autonomic nervous system functions, the breath is one way to access the vagus nerve and thus our “rest and digest” response as a means to find balance (or homeostasis) in our system.  

Here is a simple technique to bring some awareness to your breath:  

1. Lie on your back with knees bent and feet flat on the floor about hip distance apart.  
2. Place a palm on your abdomen and breathe comfortably for a few moments, noticing the quality of your breath. Does the breath feel tense? Strained? Uneven? Shallow? Simply observe the breath without any judgment.  
3. Gradually begin to make your breathing as relaxed and smooth as possible, introducing a slight pause after each inbreath and outbreath.  
4. Once the breath feels relaxed and comfortable, notice the movement of the body. As you inhale, the abdomen naturally expands; as you exhale, feel the slight contraction of the abdomen. In a gentle way, try to actively expand the abdomen on the inhale and contract the abdomen on the exhale to support the natural movement of the diaphragm and experience the pleasure of giving yourself a full, relaxed breath.   
5. Continue the practice for 6 – 12 breaths.  
6. Take a few moments after the practice to observe and notice how you feel physically, mentally, and emotionally after spending a few moments focused on your breath.  

Paying attention to the breath can be exhilarating and expansive at times and downright aggravating at others. I’ve left my breath-centered practices feeling amazingly calm and breathing more fully than ever and I’ve also left them feeling agitated that I couldn’t find ‘the groove’ that day. Stick with it. This teaches the practice of patience and allows us to check in with why we react the way we do when things don’t go our way. As with all things, practicing breathwork can go a long way. Think of that breath awareness as a muscle – the more we practice training that muscle, the stronger it gets.  

Stop.  Slow Down. And Breathe.  

Valerie Knopik is the department head and the Ben and Maxine Miller Professor of Human Development and Family Science in the College of Health and Human Sciences. Her research focuses on joint effects of genetic, epigenetic and environmental (specifically prenatal and early postnatal) risk factors on birth outcomes, externalizing behavior (ADHD, conduct disorder), associated learning and cognitive deficits, and subsequent substance use. She is also interested in the role of stress on both physiological health and mental health/wellness and the effects of yoga and mindfulness on quality of life and well-being.

References:   

Kromenacker BW, Sanova AA, Marcus FI, Allen JJB, Lane RD. Vagal Mediation of Low-Frequency Heart Rate Variability During Slow Yogic Breathing. Psychosom Med. 2018;80(6):581-587. doi:10.1097/PSY.0000000000000603  

Porges SW. Orienting in a defensive world: mammalian modifications of our evolutionary heritage. A Polyvagal Theory. Psychophysiology. 1995;32(4):301-318. doi:10.1111/j.1469-8986.1995.tb01213.x   

Senthilnathan S, Patel R, Narayanan M, et al. An investigation on the influence of yogic methods on heart rate variability. Ann Noninvasive Electrocardiol. 2019;24(1):e12584. doi:10.1111/anec.12584  

Thayer JF, Lane RD. Claude Bernard and the heart-brain connection: further elaboration of a model of neurovisceral integration. Neurosci Biobehav Rev. 2009;33(2):81-88. doi:10.1016/j.neubiorev.2008.08.004