Breathwork: a priori, it does works.

If you only have a few seconds:

A meta-analysis of randomised controlled trials has shown that breathwork is beneficial for managing stress and possibly anxiety and depression. Another study showed that mindfulness meditation and various conscious breathing techniques are all beneficial for managing one’s emotional state. But one breathing technique stands out from the rest: ‘snif snif pfff’.

…if you have a few minutes, read on…

The year 2023 is off to a strong start for the science of conscious breathing. Firstly, a research paper by the well-known wellness blogger and yet associate professor at Stanford University, Andrew Huberman ¹. This interesting article is published in a good quality scientific journal. Breathing has been studied scientifically for a very long time, but this is mainly related to medical, physiological or pathological aspects. In contrast, conscious breathing, i.e. the practice of specific and intentional breathwork, is much less studied. Moreover, studies are often of questionable quality (few subjects, dubious controls, etc.). The article in question, by Balban et al., has the merit of giving a nice spotlight on the science of conscious breathing ¹. In addition, a meta-analysis reviews the effectiveness of conscious breathing in relation to stress and mental health ². The journal is less prestigious (but still quite respectable) but it is a meta-analysis, i.e. an analysis of several independent analyses. Meta-analyses are among the most robust tools for drawing a conclusion. I suggest we discuss these two articles. Help yourselves to coffee or tea. Let’s go.

Conscious breathing is globally useful for stress management and mental health

Before embarking on the main course ¹, let’s start by tasting a meta-analysis on the effects of conscious breathing ². Breathwork offers hope for alleviating the growing ravages of chronic stress, depression and anxiety. Indeed, it is an easier and quicker alternative to be implemented on a large scale than a follow-up by a psychotherapist. That said, in order to propose breathwork as an intervention, reliable data on its effectiveness are needed. In order to answer this question, Fincham et al. reviewed, sorted and analysed the available data in the form of randomised controlled trials in which participants were asked to provide an assessment of their mental health status after a period of conscious breathing practice. From several hundred references, the authors were able to select 12 studies, including a total of 785 participants, on the effect of breathwork on stress. On average, these data indicate a beneficial effect of conscious breathing practice on stress management. Furthermore, out of the 12 studies, 10 studies involved slow-paced breathwork while the other 2 involved fast-paced breathwork. The beneficial effects are only significant for the interventions where the breathwork is slow. Nevertheless, according to the authors, the sample size is a priori too small to conclude with certainty on the supposed superiority of slow breathing over fast breathing in stress management. Important details: the benefits are significant when taught individually, in a group, in person or via video conference. Other batches of studies were analysed to conclude on possible benefits of conscious breathing on anxiety and depression. The statistics again show a tendency towards a beneficial action, but the results seem less robust than for stress and need more confirmation.

In the end, this study cautiously indicates that the practice of conscious breathing would have real benefits on stress management and also on anxiety and depression. But as it stands, this study suggests that it should be used as a complement to the tools currently available for these problems, not as a replacement. Finally, the authors emphasise that the data are mostly very recent, reflecting the current interest in conscious breathing, whereas meditation benefits from two or three decades of study. The science of conscious breathing is still young, but already promising.

Are you still hungry for knowledge? If so, so much the better, there’s a big chunk of it waiting for us.

Conscious breathing vs. mindfulness, inspiration vs. expiration

Andrew Huberman’s team wanted to compare the effects of meditation (the method of mindfulness by focusing on one’s own breathing) with those of breathwork. In this mindfulness practice, there is no active intervention on the breath, just passive observation. In contrast, the practice of conscious breathing is precisely about actively intervening in your breathing to make it follow a specific pattern. In this case, they tested three conscious breathing techniques that differed in their ratio of inhalation to exhalation time. This is an important point to note. Very often in articles about conscious breathing, breathing patterns are tested without really knowing why. The authors simply say “we made the subjects breathe like this and we observed that”. In the present article, the protocol is well structured and can be summarised as follows: Is it more effective to observe or to intervene on one’s breathing? And is it better to emphasize on inhaling or exhaling?

But before we see the results, what were these breathing patterns?

– The “snif snif pfff”: this involves taking an inhalation in two stages, like a sigh, before exhaling in deep relaxation. Exhalation is then favoured.

– The box breathing: a sequence of inspiration-retention-expiration-retention with equal durations for each phase. The duration is determined individually according to a small test which is assumed to be a CO₂ sensitivity test.

– Diet-WHM: the subject performs about 30 hyperventilations (favouring inhalation over exhalation) before recovering with an apnea on empty lungs for 15 seconds. This is a sort of basic breathing technique of the Wim Hof Method, in a lighter version, and avoiding potential concerns about intellectual properties.

First “critical” comment, if you want to test the importance of the inspiration/expiration ratio, why didn’t you test more basic patterns (2-8, 5-5, 8-2)? But let’s move on. Another point: even if the techniques are quite well detailed in the Method section of the article, we would have liked to know a little more about their execution… Patience, we’ll come back to that. For the moment, let’s remember that the hundred or so participants were divided into 4 groups (mindfulness, snif snif pfff, box, diet-WHM). Each subject then had to practice the technique he/she was assigned to for 5 minutes a day for 28 days. The subjects wore a connected bracelet that recorded a series of physiological variables (heart rate, heart variability, sleep, etc.). Each day, they also had to fill in a questionnaire about their well-being: positive affects, negative affects and anxiety state.

So what were the results?

The big winner was… (suspense)… the “snif snif pfff” technique!

Compliance with the protocol was quite good and identical for all groups (6 minutes per day, 18 days out of 28). Ninety percent of the subjects found the experience positive during the study period. One may wonder why 10% had a rather negative experience… Looking in detail, we see that the percentages vary from one group to another. The “mindfulness” and “snif snif pfff” groups had the highest rates of negative experience (12% and 17%, respectively). But then, the “negative experience” category encompasses a whole bunch of different causes (painful, tiring, boring, etc.). For mindfulness and snif snif pfff, I suspect that these accounts of negative experiences come from people who were bored. Diet-WHM registers a small 8%, benefiting, I suppose, from its “tripping” and energizing effect, but can still be too intense or even anxiety-provoking for some. Finally, it should be noted that the box breathing group did not record any negative experiences! This is interesting. Maybe it’s a sign that this fairly simple and neutral breathing technique is a good entry point for beginners: complex enough not to get bored, allowing to feel relaxed and alert at the same time, while being concentrated. In short, this is potentially interesting information for teachers of conscious breathing.

In terms of the effect of the techniques studied on positive and negative affects and anxiety, each group saw an average increase in positive affects and a decrease in negative affects and anxiety. But are these variations more or less important depending on the technique used? With regard to the average decreases in negative affect and anxiety, no. There are no significant differences between the decreases in the mindfulness and breathwork groups (where the three breathing techniques are mixed). On the other hand, as far as positive affects are concerned, the average increase observed in the breathwork groups is significantly greater than that observed in the mindfulness group. And we can even add that this increase is correlated to the number of days of practice: the more the subjects practiced, the more their positive affects increased, on average. Finally, the researchers took a closer look at the breathing techniques studied. Instead of comparing mindfulness to a breathwork group, they compared mindfulness to each of three breathworks sub-groups (snif snif pfff, box and Diet-WHM). It turns out that the “snif snif pfff” group stands out. In fact, it is the only group whose average increase in positive affect is significantly higher than that of mindfulness.

These are interesting results, no doubt about it. However, it must be borne in mind that they are the result of subjective data. Although the questionnaires answered by the participants have been validated by expert committees, they are nevertheless subjective data. But what about objective data? Such data, in this case basic physiological parameters (respiratory rate, resting heart rate, cardiac variability) could be collected during the time of the intervention thanks to the connected bracelets given to the participants. The analysis of the data shows that only the breathing rate is affected: at the end of the 28 days of the intervention, the breathing rate of the participants has little or no decrease by mindfulness (this is not clearly explained in the article), while it has significantly decreased in the breathwork group, and more particularly in the “snif snif pfff” group. The other breathing techniques did not seem to have any effect on the breathing rate after 28 days of practice. Furthermore, the authors of the study note something interesting: breathing rate and positive affect are inversely correlated. In other words, the lower the breathing rate, the higher the positive affect. But correlation is not causation, so the data do not allow us to say whether a decrease in breathing rate causes an increase in positive affect, or vice versa. Finally, the study looked at sleep. At the end of the 28-day intervention, no effect on sleep was detected. Neither on the quantity nor on the quality of sleep, nor on sleepiness during the day.

In general, and in accordance with the starting hypothesis of the authors, the study confirms that intentional control of the breath is more effective than passive observation of the breath in stimulating the parasympathetic nervous system. In this case, the “snif snif pfff” technique stands out. Remember that this technique emphasises exhalation. It is not surprising that it is more effective in stimulating the parasympathetic system than other breaths. But there is evidence here that, in a 28-day practice of 5 minutes a day, it is also more effective than mindfulness. The discussion section of the article is interesting but I don’t think it’s worth summarising here. It is about exploring the effects of mindful breathing and how to use it to better manage stress and anxiety. I encourage my readers to go directly to the article.

Why didn’t you describe the techniques better?

Scientific research is all about details. In this regard, I wanted to point out something that left me unsatisfied in this study. Basically, the act of breathing consists of moving air in and out of the lungs in a cyclical fashion. This is called ventilation. Let’s leave aside anatomical considerations (abdomen, diaphragm, thorax…) and simplify: ventilation is described mainly by the amplitude and duration of inhalations and exhalations. In this study, breathing techniques are mainly described in terms of duration, and particularly the relative durations between inhalation and exhalation. There is very little detail on amplitude. However, performing a breathing task with a regular amplitude or with a reserve amplitude does not a priori have the same impact on the autonomic nervous system. It is probable that the participants were using the reserve amplitude, but to what extent? It is impossible to know. The indications in the study are too vague on this subject. One thing that would have been welcome would have been to include the instructional videos in the Method section. The same ones that the participants received when they started this study. This would have allowed the readers to see more precisely how these techniques are done, and thus to better reproduce them at home if necessary. This is a pity, because it would have been very easy to include some video files in the Method section. This has become quite common in research articles.

Non-intentionality is not non-intervention

In this study, mindfulness is distinguished from conscious breathing in that it consists of observing one’s breathing without trying to control it. But can it be said that this practice of mindfulness only observes the breath without changing it? This is not discussed in the study… and this is unfortunate. Indeed, simply paying attention to one’s breathing slows it down ^3,4. In a medical context, on patients breathing around 15 breaths/minute, the awareness that the nurse is going to check their breathing rate slows it down by a little more than 2 breaths/minute, or about 14% ⁴. The practice of mindfulness through observation of breathing also slows breathing ³. The study does not specify by how much. However, it is reasonable to assume that the slowing down is even more pronounced when practising mindfulness at home for stress reduction purposes than in a medical context during a health check-up. In so-called “mind-body” activities (meditation, yoga, taijiquan qigong…), this slowing down of the breath would even be a common denominator explaining many of their benefits ⁵. Without necessarily trying to control the breath through specific breathing sequences, these practices nevertheless impose the slowing down of the breath and the lengthening of the exhalation, leading to relaxation… itself slowing down the breath a little more and lengthening the exhalation a little more, etc… This positive feedback loop stimulates the activity of the vagus nerve and, in the process, the parasympathetic nervous system, which in turn establishes the state of relaxation. So, if we reread the Balban et al. study with these aspects in mind, we may regret that the spontaneous breathing pattern of the “mindfulness” subjects was not characterised for comparison with the others. But one can a priori conclude from this study that slowing down the breathing and favouring the exhalation consciously is more efficient than letting things happen by themselves. To conclude, let’s go back to one point: the 28 days of mindfulness meditation did not allow the subjects to slow down their breathing rate at rest, as has been observed in the “snif snif pfff” practitioners. But it would appear that, over the long term, meditation can slow down the resting breathing rate quite significantly. Very experienced meditators breathe 1.5 times more slowly than non-meditators. This represents 2000 breaths per day (or 700,000 per year) ².

Conclusion

References:

1. Balban, M. Y. et al. Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine 100895 (2023) doi:10.1016/j.xcrm.2022.100895.

2. Fincham, G. W., Strauss, C., Montero-Marin, J. & Cavanagh, K. Effect of breathwork on stress and mental health: A meta-analysis of randomised-controlled trials. Sci Rep-uk 13, 432 (2023).

3. Tan, S.-B. et al. The Effect of 20-Minute Mindful Breathing on the Rapid Reduction of Dyspnea at Rest in Patients With Lung Diseases: A Randomized Controlled Trial. J Pain Symptom Manag 57, 802–808 (2019).

4. Hill, A., Kelly, E., Horswill, M. S. & Watson, M. O. The effects of awareness and count duration on adult respiratory rate measurements: An experimental study. J Clin Nurs 27, 546–554 (2018).

5. Gerritsen, R. J. S. & Band, G. P. H. Breath of Life: The Respiratory Vagal Stimulation Model of Contemplative Activity. Front Hum Neurosci 12, 397 (2018).