I think it’s important to provide some background on how physiologists look at stress. In physiology, the term that most accurately describes your ability to tolerate stress is “vagal tone.” This refers to the activity of your vagus nerve, which has sensory and motor functions, and runs from the brain stem to part of the colon. A medical study (McLaughlin et al., 2013) describes vagal tone as “a measure of cardiovascular function that facilitates adaptive responses to environmental challenge.” Today we discuss how your body handles stress.
The “fight or flight” response by the sympathetic nervous system is designed to prepare you for perceived danger. In the body, the manifestation of stress doesn’t discriminate. The innervation of neural pathways is essentially identical between varying stimuli. When “fight or flight” kicks in (whether you are being chased by a lion, late for work, or partaking in cold immersion), it’s up to your vagus nerve and parasympathetic nervous system (vagal tone) to bring your body to homeostasis and get you calm.
Strong vagal tone means you can handle stress well and relax faster. Poor vagal tone means sympathetic activity (elevated heart rate, blood pressure, and breathing) remains heightened after a stimulus has passed, making you far more susceptible to the many negative effects of stress over time. This is why I am writing this article- to help you improve your vagal tone and thus your quality of life.
“I tried to come up with a haiku to describe my 30-minute cold plunge experience, but ‘sympathetic expedition’ exceeded the syllable count on the third line. A shame.”
Number One: Cold Exposure
Acute cold exposure has been shown to activate the vagus nerve and activate cholinergic neurons through vagus nerve pathways. Exposing yourself to cold on a regular basis can lower your sympathetic “fight or flight” response and increase parasympathetic activity through the vagus nerve. Finishing a shower with cold water, taking a dip in the cold plunge at the spa, cryotherapy, or an ice bath will do the trick
Number Two: Deep and Slow Breathing
According to a medical report (Wang et al., 2010), “slow abdominal breathing combined with EMG biofeedback is an effective intervention to manage prehypertension. The possible mechanism is that slow abdominal breathing combined with EMG biofeedback could reduce sympathetic activity and meanwhile could enhance vagal activity.”
The conclusion to draw from this is to perform diaphragmatic breathing. When you do this, your stomach should expand outward. Your exhale should be long and slow. This is key to stimulating the vagus nerve and reaching a state of relaxation. Learn more about my recommended breathing techniques here.
Number Three: Meditation and Yoga
A medical report (Breit et al., 2018) about the vagus nerve stated that “since the vagal tone is correlated with capacity to regulate stress responses and can be influenced by breathing, its increase through meditation and yoga likely contribute to resilience and the mitigation of mood and anxiety symptoms.” Yoga also increases GABA, a calming neurotransmitter in your brain, by stimulating vagal afferent nerves, which increase activity in the parasympathetic nervous system. It’s a very effective way to help your body deal with stress more effectively.
Number Four: Exercise
“Elite endurance athletes display exceptionally high parasympathetic vagal tone,” according to a report (Machhada et al., 2017.) They also concluded that “indirect measures of high cardiac parasympathetic activity correlate with enhanced exercise capacity and lower all-cause mortality in athletes and the general population.” To paraphrase, exercising regularly has been scientifically proven to help your body deal with stress.
If you have any questions about vagal tone or stress management, feel free to leave a comment below and I’d be happy to discuss.
References:
- Breit, S., Kupferberg, A., Rogler, G., & Hasler, G. (2018). Vagus Nerve as Modulator of the Brain–Gut Axis in Psychiatric and Inflammatory Disorders. Frontiers in Psychiatry, 9, 1. https://doi.org/10.3389/fpsyt.2018.00044
- Jungmann, M., Vencatachellum, S., Van Ryckeghem, D., & Vögele, C. (2018). Effects of Cold Stimulation on Cardiac-Vagal Activation in Healthy Participants: Randomized Controlled Trial. JMIR Formative Research, 2(2), e10257. https://doi.org/10.2196/10257
- Machhada, A., Trapp, S., Marina, N., Stephens, R. C. M., Whittle, J., Lythgoe, M. F., Kasparov, S., Ackland, G. L., & Gourine, A. V. (2017). Vagal determinants of exercise capacity. Nature Communications, 8(1), 1. https://doi.org/10.1038/ncomms15097
- McLaughlin, K. A., Rith-Najarian, L., Dirks, M. A., & Sheridan, M. A. (2013). Low Vagal Tone Magnifies the Association Between Psychosocial Stress Exposure and Internalizing Psychopathology in Adolescents. Journal of Clinical Child & Adolescent Psychology, 44(2), 314–328. https://doi.org/10.1080/15374416.2013.843464
- Wang, S.-Z., Li, S., Xu, X.-Y., Lin, G.-P., Shao, L., Zhao, Y., & Wang, T. H. (2010). Effect of Slow Abdominal Breathing Combined with Biofeedback on Blood Pressure and Heart Rate Variability in Prehypertension. The Journal of Alternative and Complementary Medicine, 16(10), 1039–1045. https://doi.org/10.1089/acm.2009.0577
