The science behind breathwork
The Tao is the breath that never dies. It is a Mother of All Creation. It is the root and ground of every soul. - Tao Te Ching
Breathwork, pranayama, breath control. Many names with knowledge and techniques rooted in South and East Asia, controlled breathing has been known to alter consciousness for thousands of years. Now the science can help to explain how.
Breathing happens automatically, yet it is one of the few autonomic processes we can consciously control. This makes deliberately breathing a powerful bridge between the subconscious and conscious mind, allowing us to shift our brain-body state in real time.
The biomechanics:
To understand why different techniques produce specific effects, there’s a couple of things to understand first.
The balance between oxygen (O2) and carbon dioxide (CO2). While often viewed simply as waste, CO2 is essential for health because it changes the shape of hemoglobin, allowing it to release oxygen into your cells and tissues.
So, if you "overbreathe" by taking too many shallow breaths, you exhale too much CO2 (ironically leading to decreased oxygen delivery to the brain, which can cause or influence anxiety and lack of focus)
Your breathing is not isolated from the rest of the body. It is connected, and partly drives your nervous system.
Breathing is hard-wired to your heart rate through respiratory sinus arrhythmia
When you inhale, your diaphragm moves down, your heart gets slightly larger, and blood flow slows, prompting the brain to speed up the heart. When you exhale, the diaphragm moves up, the heart gets smaller, and the brain sends a signal via the vagus nerve to slow the heart down.
It’s also worth understanding more about the nervous system, which receives these signals and influences other processes in our bodies. The autonomic nervous system regulates involuntary bodily processes such as heart rate, digestion, and arousal. It operates unconsciously to self-regulate, featuring two main branches: sympathetic ("fight or flight") and parasympathetic ("rest and digest").
What all of that means:
Slower, more controlled breathing tends to shift the body toward a calmer autonomic state (like full Yogic breath and box breathing).
While faster breathing tends to reduce parasympathetic influence and can support a more activated state (like Kapalbhati).
So breathing does not just “respond” to the autonomic nervous system, it’s one of the few ways to deliberately influence it.
Trying it first with a practitioner can help you understand these mechanics, and also observe or your response is generally recommended. There are states where breath retention is avoided, like low-blood pressure and pregnancy. Or where techniques are moved through more carefully with observation, if you experience anxiety or have experienced a trauma.
But generally breath control is safe, and by practicing just five minutes of controlled breathing daily, you can train your nervous system to be more resilient. Leading to better sleep, lower resting heart rates, and positively influence your mood and focus.
Beyond immediate mood shifts, regular diaphragmatic breathing, where you focus on expanding the stomach rather than the chest has significant clinical benefits and is shown to reduce symptoms of some chronic health conditions.
Want to read more? Check out the sources used here:
Breathwork Protocols for Health, Focus & Stress (2023)
Brief structured respiration practices enhance mood and reduce physiological arousal (2023)
Effects of Diaphragmatic Breathing on Health: A Narrative Review (2020)
Parasympathetic Stimuli on Bronchial and Cardiovascular Systems in Humans (2015)