Conclusion
SAID
To the best of our knowledge, we designed the largest and one of the most robust, blinded RCTs exploring coherent breathing, and breathwork in general. Both interventions were masked as rhythmic breathing (equal inhale:exhale ratios and no deliberates pauses) at a rate of ~ 5.5 bcpm (CB) versus 12 bcpm (placebo), the lower bound pace of typical resting adult respiration rate. Importantly, both breathwork practices demonstrated equal plausibility in terms of credibility and expectancy of benefit, paired with similar adherence, engagement and positive sentiment. The study suggests that remote delivery of a 4-week unsupported, blinded CB intervention of ~ 10 min/day did not have any measurable effect over and above a well-designed placebo at improving mental health and wellbeing. This is not to say CB in general does not help people—this finding may be related to our intervention approach and methods, and sentiment was largely positive towards the CB protocol (along with the placebo). In summation, CB may have effects, but not on what we measured. Perhaps the effects are more physiological than psychological, or effects may be more immediate and more transient than our measurement regime was able to capture. The intervention could have been inadequate (too brief, not done correctly, with not enough context) and the comparator could have been an inadvertent active intervention, through the action of (slow)paced, abdominal/diaphragmatic and/or nasal breathing methods.Results such as this from a rigorous study help to calibrate hype with evidence for (slow) breathwork early on in this emerging research field’s development. Future research is needed to explore the potential for brief, unsupported CB interventions, but must also focus on developing more intensive, personalised CB interventions with equally well-matched placebos in order to categorically determine if CB itself is specifically effective or not at improving mental health and wellbeing. The same can be said for myriad breathwork techniques in general and we hope our methodological considerations raised can help future breathwork research and practice, in a time where simple and effective tools for fostering stress resilience are needed most.