This informal CPD article ‘Breath, Stress and Nervous System Regulation’, was provided by The Breathwork Reset, who offer transformative breathwork and meditation techniques combining ancient pranayama breathing methods with guided visualisation and modern music technology using the Soma Breathwork Protocol.
The autonomic nervous system is the system that controls the body’s automatic functions. Things like heart rate, blood pressure, body temperature, and pupil dilation are regulated continuously, outside of our conscious awareness, without us having to think about them. [1][2]
The breath is unique because it is one of the few automatic processes that we can also consciously control. This gives us a direct access point for influencing those unconscious processes and altering our physiology. That is especially powerful because breathing is a master process that affects many other internal functions. [1][2][3]
Consider for a moment, if we could consciously control pupil dilation. This would affect vision and perception, but the effects would be relatively localised. The breath, on the other hand, influences the entire body. It brings in oxygen, which supports almost every cell in the body. Red blood cells are a useful exception to note, as they transport oxygen rather than using it in the same way as most other cells. Because breathing affects oxygen delivery, carbon dioxide balance, heart rhythm, and nervous system signalling, it gives us a major opportunity to regulate our internal state. [1][3][4]
The autonomic nervous system has two main branches, commonly described as the sympathetic and parasympathetic nervous systems. These are often simplified as fight or flight and rest and digest. In stress-management terms, it is helpful to think of them as the body’s stress response and relaxation response. [2][5]
When the sympathetic nervous system becomes dominant, heart rate rises, breathing becomes faster and shallower, the mouth may become dry, the palms may sweat, and the body prepares for action. [5][6]
The problem is that the human stress response evolved mainly for short-term physical threats. It prepares us to run, fight, or otherwise act quickly. Modern stress is often different. Many of our stressors are psychological, low-grade, and constant, while our lives are often sedentary. This can lead to repeated or chronic activation of the stress response, which is harmful to health over time. In the past, physical action often helped complete the stress cycle. Today, when stress is triggered while sitting at a desk, driving, or staring at a screen, the body may remain activated for longer than is helpful. [5][7][8]
Ways the breath influences the nervous system and helps us switch between stress and relaxation:
1. Direct signalling and feedback loops
The brain sends signals to the body telling it how to respond, but the body is also constantly sending information back to the brain. Breathing is central to this two-way communication. When we are stressed, the breath usually becomes faster, shallower, and more irregular. On the other hand, when we continue to breathe in that fast, shallow way, this can reinforce the message to the brain that we are under threat. This creates a feedback loop. A good way to think of it is that the brain sends signals to the body to tell it what to do, and the body sends signals back to help the brain decide what to do next. By deliberately slowing and smoothing the breath, we can begin sending the opposite signal back to the brain: that we are safe enough to settle. [2][3][6][9]
2. Changing the speed of the heart
This is partly mechanical and partly neurological. As we breathe, the diaphragm moves and pressure changes occur within the chest. These changes influence the heart, which tends to speed up slightly on the inhale and slow down slightly on the exhale. This natural pattern is called respiratory sinus arrhythmia and is a healthy sign of nervous system flexibility. When we lengthen the exhale, we extend the period during which the heart is slowing, which can reduce overall heart rate and support a calmer state. The heart also sends important signals back to the brain, so a slower, steadier heart rhythm can contribute to a sense of safety and emotional regulation. [3][9][10]
Respiratory sinus arrhythmia
3. Changing carbon dioxide levels
Carbon dioxide is often misunderstood. It is not just a waste gas. It plays an important role in regulating blood pH, blood vessel tone, and the release of oxygen from haemoglobin into the tissues. Carbon dioxide is produced continuously by the body’s metabolism and removed through exhalation. When we overbreathe or breathe too quickly, we can blow off too much carbon dioxide, which may contribute to symptoms such as light-headedness, tingling, chest tightness, and increased anxiety. Slower, more controlled breathing can help maintain a healthier carbon dioxide balance, which often has a calming and stabilising effect on both body and mind. [3][11]
4. Vagus nerve stimulation
The vagus nerve is one of the main nerves involved in the parasympathetic, or rest-and-digest, response. It helps regulate heart rate, digestion, inflammation, and recovery. Slow breathing, especially with a longer exhale, can increase vagal activity. In simple terms, this means it helps activate the body’s calming system. As vagal tone improves, the body becomes better able to shift out of stress mode and return to a more regulated state. This is one of the reasons slow, steady breathing can help people feel calmer, more grounded, and more emotionally balanced. It is not magic, and it does not instantly switch off all stress, but it can be a very effective way to support nervous system regulation over time. [3][9][10]
Breathwork is powerful because it gives us a practical way to influence systems that normally run outside conscious control. By changing the rhythm, depth, and pattern of the breath, we can begin to influence heart rate, nervous system activity, emotional state, and mental clarity. In that sense, the breath becomes a bridge between the conscious mind and the automatic processes of the body. [2][3][9]
We hope this article was helpful. For more information from The Breathwork Reset, please visit their CPD Member Directory page. Alternatively, you can go to the CPD Industry Hubs for more articles, courses and events relevant to your Continuing Professional Development requirements.
References
[1] Homma, I., & Masaoka, Y. (2008). Breathing rhythms and emotions. Experimental Physiology, 93(9), 1011–1021.
Supported here via broader interoception/breathing reviews. https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2015.00763/full
[2] Farb, N., Daubenmier, J., Price, C. J., Gard, T., Kerr, C., Dunn, B. D., et al. (2015). Interoception, contemplative practice, and health. Frontiers in Psychology, 6, 763. https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2015.00763/full
[3] Zaccaro, A., Piarulli, A., Laurino, M., Garbella, E., Menicucci, D., Neri, B., & Gemignani, A. (2018). How breath-control can change your life: A systematic review on psycho-physiological correlates of slow breathing. Frontiers in Human Neuroscience, 12, 353. https://www.frontiersin.org/journals/human-neuroscience/articles/10.3389/fnhum.2018.00353/full
[4] Gerritsen, R. J. S., & Band, G. P. H. (2018). Breath of Life: The respiratory vagal stimulation model of contemplative activity. Frontiers in Human Neuroscience, 12, 397. https://pmc.ncbi.nlm.nih.gov/articles/PMC6189422/
[5] McEwen, B. S., & Gianaros, P. J. (2011). Stress- and allostasis-induced brain plasticity. Annual Review of Medicine, 62, 431–445. https://pubmed.ncbi.nlm.nih.gov/20707675/
[6] Tipton, M. J., Harper, A., Paton, J. F. R., & Costello, J. T. (2017). The human ventilatory response to stress: rate or depth? Experimental Physiology, 102(12), 1549–1552. https://pmc.ncbi.nlm.nih.gov/articles/PMC5577533/
[7] Dhabhar, F. S. (2018). The short-term stress response – Mother nature’s mechanism for enhancing protection and performance under conditions of threat, challenge, and opportunity. Frontiers in Neuroendocrinology, 49, 175–192. https://pubmed.ncbi.nlm.nih.gov/29596867/
[8] Dėdelė, A., Miškinytė, A., Andrušaitytė, S., & Bartkutė, Ž. (2019). Perceived stress among different occupational groups and the interaction with sedentary behaviour. International Journal of Environmental Research and Public Health, 16(23), 4595. https://www.mdpi.com/1660-4601/16/23/4595/notes
[9] Balban, M. Y., et al. (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 4(1). https://pubmed.ncbi.nlm.nih.gov/36630953/
[10] You, M., et al. (2021). Single slow-paced breathing session at six cycles per minute: Investigation of cardiac vagal activity. https://pmc.ncbi.nlm.nih.gov/articles/PMC8656666/
[11] Laborde, S., et al. (2021). Slow-paced breathing: Influence of inhalation/exhalation ratio and respiratory pauses on cardiac vagal activity. Sustainability, 13(14), 7775. https://www.mdpi.com/2071-1050/13/14/7775
