the science Of breath
we take around 20,000 to 25,000 breaths each day
most of them happen without awareness
Breathing is one of the few bodily functions that is both automatic and consciously controllable. Because of this, it provides a direct pathway into regulating the nervous system, physiology, and internal state. At the centre of healthy breathing is the diaphragm, a large dome shaped muscle beneath the lungs. When the diaphragm moves freely, it draws air deep into the lungs on the inhale and releases gently on the exhale. This supports efficient gas exchange, reduces tension in the neck and shoulders, and signals safety to the nervous system. Chronic stress, emotional tension, pain, posture, or trauma can restrict diaphragmatic movement. Over time, this contributes to shallow or erratic breathing patterns and keeps the body in a subtle state of alert. Breathwork can support more functional breathing patterns and help the nervous system return toward balance.
the autonomic nervous system, vagus nerve and hormones
Breathing is closely linked to the autonomic nervous system, which regulates heart rate, digestion, blood pressure, immune function, and hormonal balance.
• the sympathetic nervous system governs survival responses; fight, flight, freeze
• the parasympathetic nervous system supports rest, repair, digestion, and recovery
One of the main pathways influencing this balance is the vagus nerve (the wandering nerve), which connects the brain to the heart, lungs, and digestive organs. Gentle, slow, and continuous breathing stimulates the vagus nerve, increasing parasympathetic activity and reducing sympathetic dominance.
This shift influences hormonal regulation. Stress driven breathing patterns are associated with elevated cortisol and adrenaline. Breathwork practices that support parasympathetic activation can help reduce stress hormone output and support the regulation of hormones involved in mood, sleep, digestion, and immune function.
breath, the heart, and heart rate variability
Breathing and heart rate are closely coupled through respiratory sinus arrhythmia. When we inhale, heart rate increases. When we exhale, heart rate slows. Heart rate variability (HRV) refers to the variation in time between individual heartbeats. Higher HRV indicates a nervous system that is flexible and responsive rather than rigid or chronically stressed. Lower HRV is commonly associated with anxiety, burnout, and prolonged stress. Breathing practices that emphasise slower rhythms and longer exhales tend to increase HRV, supporting resilience, emotional regulation, and recovery.
breath, the brain, and memory
Breathing patterns influence brain activity, particularly in regions involved in emotion, memory, and self awareness. Research shows that changes in breathing rhythm affect communication between the brainstem, limbic system, and cortex.
Under stress, the brain prioritises survival and often suppresses access to memory and emotional processing. When the nervous system settles through breathwork, activity in the prefrontal cortex and limbic regions becomes more integrated. This allows memories, emotions, and sensations that were previously inaccessible to come into awareness.
This is not regression or reliving the past. It is the nervous system shifting into a state where information stored outside of conscious awareness may come into awareness and be processed more gently.
This is also why breathwork can sometimes produce experiences of clarity, insight, or emotional release that feel similar to those reported in certain psychedelic states. In both cases, default patterns of brain activity temporarily loosen, allowing new connections, memories, and perspectives to emerge. Breathwork achieves this through physiological regulation rather than external substances.
different breathing patterns and their effects
Different breathing approaches create different physiological responses:
• Longer exhales - support calming, grounding, and nervous system settling
• Shorter or faster breaths - increase alertness and energy
• Gentle breath holds - can heighten internal awareness and influence regulatory reflexes
temperature changes and tetany
During practices such as Clarity Breathwork, continuous connected breathing can temporarily shift blood chemistry and nervous system signalling.
Temperature changes may occur due to changes in circulation and blood vessel dilation as the nervous system shifts state.
Tetany refers to temporary muscle tightening or tingling, often in the hands, mouth, or feet. This occurs when breathing patterns reduce carbon dioxide levels in the blood, which affects calcium availability at the neuromuscular junction. The result can be brief, involuntary muscle contractions.
Tetany is:
• a known physiological response
• temporary and self resolving without intervention
• eased by slowing the breath and grounding the body
• generally harmless and not a sign of injury
a living science
Breath based practices are increasingly researched within neuroscience, psychology, and trauma informed healthcare. The evidence consistently shows that breathing is one of the most direct and measurable tools for influencing nervous system regulation, hormonal balance, emotional processing, and overall wellbeing.
Breathwork does not force change.
It creates conditions in which regulation, insight, and integration can emerge naturally
ongoing research
Breath based practices are increasingly recognised within healthcare, psychology, and neuroscience. Research from institutions such as Harvard Medical School, Stanford University, and the National Institutes of Health has explored how breathing affects the nervous system, stress physiology, and emotional regulation.
This growing body of research continues to highlight the breath as a simple, accessible, and deeply intelligent resource for supporting physical, emotional, and nervous system health.
• Harvard Medical School
Breath control and relaxation response
https://www.health.harvard.edu/mind-and-mood/relaxation-techniques-breath-control-helps-quell-errant-stress-response
• Stanford University
https://stanmed.stanford.edu/cyclic-sighing-stress-relief/
• The National Institutes of Health (NIH)
https://pmc.ncbi.nlm.nih.gov/articles/PMC10741869/
If you are interested in exploring the science further, links to published studies and research can be found through these institutions and peer reviewed journals.
