In a groundbreaking study published in Scientific Reports, researchers have found that coherent breathing, a popular relaxation technique, may not be more effective than a placebo in reducing stress or improving mental health. The findings, emerging from one of the largest and most robustly controlled trials in this area, suggest that the benefits of coherent breathing, as delivered in the study, may not be as significant as previously thought.
Breathwork, the practice of consciously controlling one’s breathing pattern, has been a subject of interest for centuries, often linked to various health benefits. Coherent breathing, in particular, involves regulating breaths to a specific rhythm and has been thought to synchronize respiratory and cardiovascular functions. This practice, deeply rooted in various cultural and spiritual traditions, has seen a surge in popularity, with many adopting it for its purported benefits in reducing stress, anxiety, and improving overall wellbeing. This surge in interest, coupled with anecdotal success stories, prompted scientists to investigate the true efficacy of coherent breathing in a controlled setting.
“Coherent breathing (aka resonant frequency breathing, resonant breathing, coherence breathing, HRV-biofeedback breathing) is a very simple type of breathwork which has been known for its psychophysiological benefits. However, no extremely robust randomized controlled trials of this type of breathing and subjective mental health/wellbeing have been completed (see previous meta-analysis and/or PsyPost article),” said study author Guy W. Fincham (@breath_Guy), a PhD breathwork researcher at the Psychology and Medical Schools at the University of Sussex and fellow of the Ryoichi Sasakawa Young Leaders Fellowship Fund.
“We wanted to compare daily coherent breathing to a placebo for ~1 month to see if there were any differences on subjective mental health and wellbeing outcomes. We also wanted to create a placebo with equal credibility and expectancy of benefit, and blind participants to their allocated intervention (masking/concealment) both of which were paced with equal inhalation:exhalation ratios.”
The study, conducted online through the research platform Prolific, involved 400 participants. To ensure a diverse sample, the study included individuals from various backgrounds, with the majority being female and of White ethnicity. Participants were required to be 18 or older, able to breathe through their nose, and have access to headphones. Exclusion criteria were set to omit those with conditions that might affect breathing, such as respiratory or cardiovascular issues.
Participants were randomly assigned to one of two groups. The first group practiced coherent breathing at approximately 5.5 breaths per minute for about 10 minutes daily over four weeks. This intervention was delivered through pre-recorded guidance by a trained facilitator (see here).
The second group, serving as a control, was given a placebo breathing exercise at 12 breaths per minute, matching the intervention in all aspects except the breathing pace (see the placebo intervention here). This rate was chosen as it aligns with the lower end of the average resting respiration rate for adults, thereby making it a credible yet distinct comparison to the coherent breathing practice.
The study’s primary outcome was stress, measured using the Depression Anxiety Stress Scale-21 (DASS-21) stress subscale. Secondary outcomes included measures of anxiety, depressive symptoms, wellbeing (assessed via the World Health Organisation-5 Well-Being Index), and sleep disturbance (evaluated using the PROMIS Item Bank v1.0—Sleep Disturbance—Short Form 8a scale). Additionally, the Credibility/Expectancy Questionnaire (CEQ-6) was employed to gauge participants’ beliefs and expectations about the effectiveness of their assigned breathwork protocol.
Surprisingly, the results revealed no significant difference between the coherent breathing group and the placebo group in reducing stress. Both groups showed an overall improvement in stress scores from baseline to post-intervention, but the improvement was not different between groups.
Similarly, for anxiety, depression, wellbeing, and sleep disturbance, there were no significant differences in outcomes between the two groups. Both groups reported an improvement in anxiety and depression scores and an increase in wellbeing scores over time, with no significant changes in sleep disturbance scores.
“This was the largest randomized-controlled trial on breathwork to date (400 participants!). There were no differences on credibility and expectancy of benefit between the coherent breathing and placebo breathwork. There were overall improvements on mental health and wellbeing outcomes (except from sleep disturbance — no change) from baseline to post-intervention and follow-up across both groups, yet the magnitude of this improvement was not different between the groups,” Fincham told PsyPost.
“Accordingly, we found no measurable effect of coherent breathing over and above a well-designed breathwork placebo at improving mental health and wellbeing. This is not to say coherent breathing in general does not help people — this finding may be related to our intervention approach and methods, and sentiment was largely positive towards both the coherent breathing protocol (along with the placebo breathwork). I am now supervising a student who is analyzing all of the qualitative response data which will provide much greater context, and we hope to publish later this year.”
While these findings are intriguing, they come with limitations. One limitation is the remote, non-personalized delivery of the intervention, which lacked real-time feedback and may not have fully captured the essence of coherent breathing practices. Additionally, the study’s design, focusing on a single, standardized breathing practice, might not have reflected the full potential of coherent breathing, which could be more effective when tailored to individual needs and delivered in a more personalized manner.
“We need to ensure that adherence is not just subjective self-report and that it is objective and trackable,” Fincham explained. “However, as a PhD/doctoral researcher with limited resources, it’s difficult to balance doing a remote trial with recruiting the greatest number of participants possible versus being able to objectively track adherence (i.e., via giving participants’ the best wearables possible for the study and then tracking them ‘in the wild’).
“In short, essentially, the trade-off is between recruiting the largest sample and highest quality study design possible. Measuring heart-rate variability (HRV — the most significant purported benefit of coherent breathing, especially physiological) in the ~5.5b/min and placebo (12b/min) group would’ve been great, and/or increasing the practice time to 20min/day (though this may not have been deemed feasible by many!). Hopefully, we can do this in the future at Brighton & Sussex Medical School.”
“Ultimately, I hope my work can help build a larger evidence-based picture of the psychophysiological effects (and potential efficacy) of breathwork,” Fincham added. “I wish to set up ‘Brighton & Sussex Breathwork Lab,’ dedicated to breathwork research and practice (funders/donors reach out if interested!) and am open to advisory/consulting roles, including coaching. I have a growing interest in the innumerable applications of breathwork across all contexts of human recovery and performance, from health to sports.”
“I recently published this huge narrative review in the journal Neuroscience & Biobehavioural Reviews on intensive, fast-paced breathwork too (what we have deemed as ‘High ventilation breathwork’— the rubric being HVB): https://www.sciencedirect.com/science/article/pii/S0149763423004220.”
The study, “Effect of coherent breathing on mental health and wellbeing: a randomised placebo-controlled trial“, was authored by Guy W. Fincham, Clara Strauss, and Kate Cavanagh.
