A curated reference to the peer-reviewed research
on breathwork, conscious breathing, and nervous system regulation.
Primary sources. Plain English context.
Honest about what the evidence does and does not show.

The most well-established area of breathwork research. Slow breathing — typically defined as six breaths per minute or fewer – consistently produces measurable effects on autonomic nervous system activity across multiple research groups and methodologies.

Key findings:
Slow breathing increases parasympathetic activity and decreases sympathetic activity. It reduces blood pressure in hypertensive populations. It improves heart rate variability – a key marker of nervous system resilience. Effects are measurable within a single session and cumulative with regular practice.

Primary sources:
Zaccaro et al. (2018) – How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing. Frontiers in Human Neuroscience.
Jerath et al. (2015) – Self-regulation of breathing as a primary treatment for anxiety. Applied Psychophysiology and Biofeedback.

Heart rate variability is the measure most consistently used in breathwork research. A higher HRV indicates a more adaptable, resilient nervous system. Coherence breathing – an equal inhale and exhale at approximately five to six breaths per minute – is among the most well-documented interventions for improving HRV.

Key findings:
Coherence breathing at resonance frequency produces measurable improvements in HRV in both clinical and non-clinical populations. Effects are maintained beyond the session in regular practitioners. Improvements in HRV are associated with reductions in anxiety, depression, and cardiovascular risk markers.

Primary sources:
Lehrer and Gevirtz (2014) – Heart rate variability biofeedback: how and why does it work? Frontiers in Psychology.
Steffen et al. (2017) – Psychophysiological correlates ofresonance frequency breathing. Biofeedback.

A growing body of research documents breathwork’s effects on clinical and sub-clinical anxiety, perceived stress, and cortisol – the primary stress hormone.

Key findings:
Diaphragmatic breathing interventions reduce cortisol and improve measures of sustained attention and mood. Slow breathing reduces anxiety scores across multiple validated measures. Breathwork programmes in clinical populations show comparable outcomes to other evidence-based interventions for mild-to-moderate anxiety.

Primary sources:
Perciavalle et al. (2017) – The role of deep breathing on stress. Neurological Sciences.
Ma et al. (2017) – The effect of diaphragmatic breathing on attention, negative affect and stress in healthy adults.Frontiers in Psychology. 
Zaccaro et al. (2018) – as above.

The research on birdsong and nature sounds has particular relevance to TEA’s practice – where birdsong opens every session and the silence between breathwork segments is held as active, tended space.

Key findings:
Birdsong produces measurable reductions in anxiety and cortisol. Positive effects on mood persist for up to eight hours following exposure – including for people living with depression. Nature sounds in general improve recovery from stress more rapidly than urban sounds, with birdsong producing the strongest reported effects.

Primary sources:
Hammoud et al. (2022) – Smartphone-based ecological momentary assessment reveals mental health benefits of birdlife. Scientific Reports.
Buxton et al. (2021) – A synthesis of health benefits of natural sounds and their distribution in national parks. PNAS.

The Kirste research is among the most cited findings in TEA’s teaching – the neurological basis for using silence as an active, intentional element of sessions rather than filler between practices.

Key findings:
Two hours of silence per day promoted new cell growth in the hippocampus of mice – a process called neurogenesis. This effect was not observed during music, speech, or white noise. The hippocampus is the brain region central to memory, learning, and emotional regulation. The mechanism is understood to involve the nervous system’s relief from constant threat-scanning that genuine silence provides.

Primary source:
Kirste et al. (2013) – Is silence golden? Effects of auditory stimuli and their absence on adult hippocampal neurogenesis. Brain Structure and Function.

The specific research on conscious connected breathwork is less extensive than the broader literature on slow breathing – but it is growing.

Key findings:
Studies on connected and conscious connected breathwork document reductions in anxiety, depression, and stress symptoms following facilitated ses…ch are noted: sample sizes are often small and the practice is inherently difficult to study in controlled conditions.

Primary sources:
Rhinewine and Williams (2007) – Holotropic breathwork: the potential role of a prolonged, voluntary hyperventilation procedure as an adjunct to psychotherapy. Journal of Alternative and Complementary Medicine.

Uthaug et al. (2021) – An experience with Holotropic Breathwork is associated with improvement in non-judgement and satisfaction with life while reducing symptoms of stress. Journal of Psychedelic Studies.

Eyerman (2013) – A clinical report of holotropic breathworkin 11,000 psychiatric inpatients in a community hospital setting.MAPS Bulletin Special Edition.