Breathing Techniques for the Nervous System: How the Breath Steers the Vagus Nerve
Your breath is the function of the autonomic nervous system that you can take over most directly. And the exhalation is the brake.
We usually look for calm on the outside. In the app, in the supplement, in the next free weekend. Yet since your very first day of life you have carried an access point around with you that is immediately available, free of charge and physiologically measurable. The catch: almost nobody has ever explained to you why it works.
You know this moment
It is Tuesday afternoon. Nothing bad has happened. And still there is something sitting in your chest. A fine vibration, as if the engine were idling at too high a speed.
You breathe shallowly. High up in the chest, short, without noticing it. Your shoulders sit a little higher than they need to. And when someone asks how you are, you say: fine, lots going on.
In the evening you lie down. The body is tired, the system is not. The thoughts keep running as if nobody had told them the day was over. At the doctor's everything was unremarkable. Blood count fine, thyroid fine, ECG fine.
Unremarkable does not mean calm. It only means that what was measured lies within the reference range. The state of your autonomic nervous system appears in none of those findings.
This is exactly where this text begins. Not with a list of breathing exercises that you find in every second reel. Rather with the question of why a particular way of breathing can change anything in the body at all. Because once you understand the mechanism, you do the exercise differently. And you are more likely to keep going.
Why the breath is the most direct access point to the autonomic nervous system
Your body has two operating modes. The sympathetic system is the accelerator: heart rate up, muscles ready, attention turned outwards. The parasympathetic system is the brake: digestion, regeneration, repair, attention turned inwards.
Both run automatically. You cannot lower your blood pressure by an act of will. You cannot switch on your intestinal motility. You cannot widen your pupils deliberately.
One function of this system you can take over directly: breathing. It keeps running automatically while you sleep. And it obeys you immediately when you take it over. That is anatomically remarkable, and it is the reason why breathwork appears in practically every body tradition in the world, long before anyone had an ECG.
Most people think of wellness when they hear about breathing exercises. A nice thing to do when there is time for it. From a physiological point of view it is something else.
Breathing is an interface. It is the place where your conscious will and your autonomic nervous system use the same nerve. Every breath is a signal to the brainstem. You cannot switch this signal off, but you can change its content.
And now you know why the conversation about breathing is worth having before we talk about a single exercise.
The vagus nerve: your body's brake line
The vagus nerve is the tenth cranial nerve. Its name comes from the Latin word for wandering, and that describes it well. It leaves the brainstem, runs down the neck and branches out to the heart, lungs, stomach, intestines, liver and spleen.
One important detail is often overlooked: the vagus is not a one way street heading downwards. The larger part of its fibres runs in the opposite direction, from the organs to the brain. Through this nerve your head receives continuous reports about how things look in the rest of you. That could be one anatomical basis of what we call a gut feeling. What is documented is the connection from organ to brain. Assigning it to the gut feeling is an interpretation, not a measurement.
At the heart the vagus works as a brake. It releases acetylcholine onto the sinus node, the body's own pacemaker. That slows the beat. When vagal influence decreases, the heart speeds up. This brake is fast. It takes hold within a single heartbeat, while the sympathetic accelerator needs seconds to work through adrenaline.
The lungs report upwards
Stretch receptors in the airways and baroreceptors in the aorta and the carotid artery send their signals through vagal fibres to the nucleus tractus solitarii in the brainstem.
The brainstem computes
The nucleus tractus solitarii passes this information on, among other places to the nucleus ambiguus, the origin of the heart slowing vagal fibres.
The vagus brakes the heart
Acetylcholine at the sinus node lengthens the interval between two beats. This becomes visible as a rise in heart rate variability, especially during exhalation.
The report goes back to the brain
Ascending pathways reach areas involved in attention, appraisal and emotion regulation. The body informs the head that there is no danger at the moment.
Three Australian pain physicians compiled the entire available physiology of slow breathing in healthy humans in the journal Breathe in 2017. They describe how slow breathing can influence diaphragm activity, ventilatory efficiency, the chemoreflex, baroreceptor sensitivity, heart rate variability and the coupling between heart and breath.
Their conclusion is restrained and therefore credible: there is a plausible physiological basis, and there is an urgent need for further research. For you that means no miracle mechanism is being claimed here, but rather a control loop that can be described well.
Russo, Santarelli, O'Rourke. The physiological effects of slow breathing in the healthy human. Breathe. 2017. DOI: 10.1183/20734735.009817Why it is the exhalation of all things that acts as the brake
Place two fingers on your wrist and breathe in slowly. If you feel closely enough, the pulse becomes slightly faster during this phase. Breathe out, and it slows down. This phenomenon is called respiratory sinus arrhythmia. It is not a fault, it is a sign of health.
The reason lies in the brainstem. During inhalation the vagal output to the heart is briefly dampened, and the heart is allowed to speed up. During exhalation this dampening falls away, the vagus takes hold again, and the heart slows down. So your breathing modulates, second by second, how firmly the brake is currently applied.
Two breathing patterns compared
A simplified depiction of the ratio between inhalation and exhalation. What matters is not the exact number of seconds, but that the exhalation takes up the larger share of the breathing cycle.
In 2019 two American physiologists formulated a detailed hypothesis about what happens in detail during the two phases. Their model is mechanistic, it rests on animal and human data from respiratory physiology, and it is the clearest explanation I currently know.
Noble and Hochman from Emory University describe in Frontiers in Physiology how a long inhalation preferentially activates slowly adapting stretch receptors in the lung, which trigger inhibitory effects in the brainstem. During a deep exhalation this receptor activity ends, while at the same time blood pressure rises briefly and stimulates the baroreceptors.
Both signals converge in the nucleus tractus solitarii. The result is a strengthened parasympathetic output to the heart during exhalation. The authors explicitly emphasise that this is a hypothesis which needs further testing in the model.
Noble, Hochman. Hypothesis: Pulmonary Afferent Activity Patterns During Slow, Deep Breathing Contribute to the Neural Induction of Physiological Relaxation. Front Physiol. 2019;10:1176. DOI: 10.3389/fphys.2019.01176If that holds true, a very practical consequence follows. A deep inhalation alone is not enough. Only the lengthened exhalation uses the time window in which the vagal brake can take hold.
A research group at Stanford University compared three breathing forms with mindfulness meditation in a randomised, controlled study over one month. Each group practised five minutes daily. The forms were cyclic sighing with an emphasised exhalation, box breathing with equally long phases, and cyclic hyperventilation with a short exhalation.
The exhalation focused variant performed best for improvement in mood and lowered respiratory rate most clearly, in each case compared with the meditation group. For you this means: not every breathing technique is the same. Emphasising the exhalation appears to be the most effective lever among those tested.
Balban, Neri, Kogon et al. Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Rep Med. 2023;4(1):100895. DOI: 10.1016/j.xcrm.2022.100895An Indian research group had 20 people with obesity breathe to a metronome with a low ratio of inhalation to exhalation, at 12 breaths per minute. The exhalation took up around 56 percent of the total breath duration. The control group sat quietly and watched the same metronome without changing their breathing.
In the intervention group, two markers of vagally mediated heart rate variability increased, RMSSD and the high frequency component. At the same time mood improved and reported tension decreased. What is interesting is that no particularly slow frequency was needed here, only a shifted ratio.
Telles, Gupta, Sharma, Balkrishna. Volitionally Regulated Breathing with Prolonged Expiration Influences Food Craving and Impulsivity. Complement Med Res. 2024;31(4):376-389. DOI: 10.1159/000539618And now you know why the old instruction to just take a deep breath so often comes to nothing. It emphasises the wrong half.
Heart rate variability: the measure where you can see it
A healthy heart does not beat like a metronome. Between two beats there are sometimes 880 milliseconds, sometimes 910, sometimes 865. This fluctuation is called heart rate variability, or HRV for short. It arises to a large extent through the vagus nerve.
The thinking error I see most often: people take a steady heart rate to be a sign of stability. Physiologically the opposite tends to be true. A system that can move flexibly between tension and relaxation produces more variability. A rigidly timed pulse at rest suggests rather that the accelerator stays permanently pressed a little.
We often talk about relaxation as if it were a state you reach and then hold. That is not how physiology works.
What is healthy is the ability to switch. Ramping up when it is necessary. And coming back down when it is over. Chronic stress shows itself less in the fact that someone is tense, and more in the fact that the return no longer happens. Breathwork trains exactly this way back.
Research has one particular breathing frequency in view: about six breaths per minute, which corresponds to roughly 0.1 hertz. In this range, breathing, blood pressure waves and heart rate swing in a shared rhythm. This is called resonance.
An Italian group around Bernardi studied 20 people with essential hypertension and 26 control persons in a seated position. Measurements were taken during spontaneous breathing as well as during controlled breathing at 6 and at 15 breaths per minute.
At six breaths per minute, systolic pressure in the hypertension group fell from 149.7 to 141.1 millimetres of mercury, and diastolic pressure from 82.7 to 77.8. Baroreceptor sensitivity rose from 5.8 to 10.3 milliseconds per millimetre of mercury. That was an acute measurement during the exercise. It is not proof of a blood pressure therapy, but it is very clear evidence that breathing frequency reaches the circulation measurably.
Joseph, Porta, Casucci et al. Slow breathing improves arterial baroreflex sensitivity and decreases blood pressure in essential hypertension. Hypertension. 2005;46(4):714-718. DOI: 10.1161/01.HYP.0000179581.68566.7dSome years earlier the same research group had observed something that still moves me today. They studied what happens in the circulation while reciting the rosary in Latin and while speaking a yoga mantra.
In 23 healthy adults, both forms of recitation led almost automatically to a breathing frequency of about six breaths per minute. With that, the existing circulatory rhythms strengthened markedly and in synchrony. Baroreceptor sensitivity rose from 9.5 to 11.5 milliseconds per millimetre of mercury.
Two forms of practice from very different cultures arrive at the same breathing frequency. The authors even consider it possible that the rosary reached Europe historically from the Indian tradition. Either way it remains remarkable that both end up at around six breaths per minute. For me that is an indication that old practice and modern physiology do not have to contradict each other.
Bernardi, Sleight, Bandinelli et al. Effect of rosary prayer and yoga mantras on autonomic cardiovascular rhythms. BMJ. 2001;323(7327):1446-1449. DOI: 10.1136/bmj.323.7327.1446The obvious question is: do I have to hit those six breaths exactly? Two studies from Cologne and Caen give a reassuring answer.
A German French group had 59 people breathe at six cycles per minute on five separate occasions, for 5, 10, 15 or 20 minutes each, plus a control condition without practice. Vagally mediated heart rate variability rose in all practice conditions compared with the control.
Between the durations no difference was found for this measure. The duration did, however, influence the spontaneous breathing frequency afterwards: it fell with longer practice time. For you that means short sessions already set something in motion, while longer ones may have a longer after effect.
You, Laborde, Zammit et al. Single Slow-Paced Breathing Session at Six Cycles per Minute. Int J Environ Res Public Health. 2021;18(23):12478. DOI: 10.3390/ijerph182312478And now you know why you do not have to hit a tenth of a second. The corridor is wider than many people think. An app can help with the rhythm. Going by the data we have so far, it is not necessary for the effect.
What your brain picks up from this
Up to here it has been about the heart and circulation. But the really interesting question is a different one: why does what you think and feel also change when you breathe?
This is where things become interesting for KPNI (Clinical Psychoneuroimmunology), because all four lenses converge. The nervous system establishes the connection. The hormonal system responds through the stress axis. Metabolism follows, because a permanently activated sympathetic system shifts how energy is used. And the immune system is attached to it, because vagal signals are involved in the regulation of inflammatory processes.
Nervous system
The breathing rhythm paces the brainstem, limbic areas and cortex. Through ascending vagal pathways the information reaches regions involved in appraisal and emotion regulation.
Hormonal system
Sustained sympathetic activation keeps the stress axis in motion. If the parasympathetic counter movement happens more often, the hormonal baseline may shift along with it.
Metabolism
Under constant activation the body switches to fast availability of energy. Regenerative processes such as digestion and repair can run better in parasympathetic mode.
Immune system
Vagal pathways are involved in dampening inflammatory signals. This is an active field of research, and for breathing techniques it remains plausible rather than proven so far.
The connection is most directly documented in the brain itself. And with a method that you normally cannot ask people to undergo.
A group at Northwestern University was able to measure directly inside the brain in patients with difficult to treat epilepsy while they breathed normally. The electrodes were already in place there for therapeutic reasons.
The result: natural breathing synchronised electrical activity in the olfactory cortex, the amygdala and the hippocampus. Activity was strongest during inhalation. As soon as breathing came through the mouth instead of the nose, the coupling became markedly weaker. In accompanying behavioural experiments, healthy participants recognised fearful faces faster when they were inhaling at that moment.
Zelano, Jiang, Zhou et al. Nasal Respiration Entrains Human Limbic Oscillations and Modulates Cognitive Function. J Neurosci. 2016;36(49):12448-12467. DOI: 10.1523/JNEUROSCI.2586-16.2016So the breath is not a purely circulatory effect. It is a pacemaker for brain areas that have to do with fear and memory. That explains quite a lot about why breathwork feels different from a circulatory exercise.
How closely breathing and wakefulness are wired together was shown in 2017 by a paper from Stanford and UCLA, although in mice. I name it explicitly as an animal study here, because its finding is often transferred to humans in a sloppy way.
In the preBötzinger complex of the mouse, the pacemaker of breathing in the brainstem, the group found a small subgroup of around 175 nerve cells. When these cells were selectively switched off, breathing remained completely normal. What changed was behaviour: the animals spent more time in calm states and less in aroused ones.
These cells project directly to the locus coeruleus, the noradrenaline centre for wakefulness and alertness. In the animal model there is therefore a direct anatomical line from the breathing pacemaker to the level of arousal. In humans a corresponding wiring has not so far been shown in this form.
Yackle, Schwarz, Kam et al. Breathing control center neurons that promote arousal in mice. Science. 2017;355(6332):1411-1415. DOI: 10.1126/science.aai7984And now you know why the line between a body exercise and a matter of the mind is so hard to draw when it comes to the breath. Anatomically it does not exist.
A pattern I often meet in practice
I deliberately describe no individual story here, but a pattern: people with persistent inner restlessness whose previous findings are unremarkable. That is a sensible and important result, because it rules out the dangerous causes. What laboratory and ECG diagnostics naturally do not show is the autonomic state. That question only comes up once the more important things have been excluded.
For many people the decisive step is then not the technique, but the one time bodily experience that something slows down at all while breathing out. Not as an idea, but as a perception.
Whether a lasting change grows out of that, I cannot predict. It depends on different factors in every person, and usually more changes in parallel than just the breathing.
Calm is not a luxury and not a reward for work completed. Calm is the precondition for being able to choose again instead of merely reacting. That is the real freedom this is about.
How robust is the evidence
I think it is important to stay honest at this point. Breathwork is currently being marketed very loudly, and the data are better than ten years ago, but they are not spectacular.
A British group around Fincham summarised randomised, controlled trials on breathwork in Scientific Reports. For self reported stress the effect size was g = -0.35, calculated from 12 studies with 785 adults. For anxiety, 20 studies arrived at -0.32, for depressive symptoms 18 studies at -0.40. All three values were statistically significant.
These are small to moderate effects. The authors themselves point out that most of the included studies had a moderate risk of bias, and they explicitly warn about a discrepancy between hype and evidence. I share that restraint.
Fincham, Strauss, Montero-Marin, Cavanagh. Effect of breathwork on stress and mental health: A meta-analysis of randomised-controlled trials. Sci Rep. 2023;13(1):432. DOI: 10.1038/s41598-022-27247-yFor HRV biofeedback, that is slow breathing with simultaneous feedback of the heart data, the balance is clearer. A group at Boston University found a pooled pre post effect size of g = 0.81 and, compared with control conditions, g = 0.83 for the reduction of self reported stress and anxiety.
Effectiveness was moderated neither by year of publication nor by the number of sessions nor by the presence of an anxiety disorder. The authors nevertheless call for further well controlled studies. The method is well investigated, but not conclusively settled.
Goessl, Curtiss, Hofmann. The effect of heart rate variability biofeedback training on stress and anxiety: a meta-analysis. Psychol Med. 2017;47(15):2578-2586. DOI: 10.1017/S0033291717001003A systematic review from Pisa examined the psychophysiological correlates of slow breathing in 2018. Out of 2,461 abstracts, 15 papers finally met the inclusion criteria. That is a thin basis, and the authors say so themselves. What they found was consistent: more heart rate variability, more respiratory sinus arrhythmia, more alpha activity in the EEG, less theta activity, and subjectively more comfort and less tension.
The physiological side is well described. That slow breathing can acutely raise vagally mediated heart rate variability and baroreceptor sensitivity has been measured independently several times.
The clinical side is weaker. Whether stable changes in anxiety, depression or blood pressure follow from this over months is not conclusively settled. Large, long term and well blinded studies are missing, and blinding is methodologically difficult with breathing exercises.
My position on this: for most people, slow breathing is a measure with low risk, no cost and a plausible physiological basis. Who it does not apply to is set out in the next section. From my point of view that justifies trying it, but not a promise.
Three levers you can apply today
I am deliberately keeping this short. Three things, not ten. Whoever takes ten exercises away ends up doing none.
Lengthen the exhalation, not the inhalation
A simple ratio: about four seconds in through the nose, about six seconds out. Without pushing, without holding. If six seconds is too long, take five. The point is the ratio, not the number.
If you notice that the exhalation runs out before the time is up, simply breathe in a little less deeply beforehand. Full lungs are not the goal here.
Five minutes, daily, tied to a fixed anchor
The available data suggest that a short session of five minutes can already raise vagally mediated heart rate variability. Whether daily practice brings more than infrequent long practice has not been studied directly. In my experience, regularity is the part that fails in everyday life, which is why I prefer to recommend short and daily.
Attach the exercise to something that happens anyway. After brushing your teeth. Before setting off. While waiting for the coffee. A fixed anchor beats good intentions.
Nose instead of mouth, belly instead of chest
The intracranial recordings show that nasal airflow itself carries the coupling between breathing and limbic areas. What they do not show is a calming effect. What was measured is a timing, not relaxation. I still recommend nasal breathing, because it makes the breath slower and more even by itself. That is the part that counts here.
Place a hand on your belly. If the hand rises as you breathe in and the shoulders stay quiet, the diaphragm is working. That is the muscle actually responsible for breathing.
Many people only bring out the breathing exercise once the tension is already high. That can work, but it is the hardest version.
The opposite makes more sense. You practise in calm so that the path is paved when things get tight. As in sport: you do not train during the competition. You train beforehand, so that the body knows what to do when the competition comes.
Where the breath reaches its limits
It would be dishonest to end this text without this section. Breathwork is not for everyone and not suitable in every form.
Situations in which restraint is appropriate
- Panic disorder with a tendency to hyperventilate: attention on the breath can initially amplify anxiety. Better to start with support.
- Poorly controlled asthma or COPD: changed breathing patterns should first be discussed with the treating practice.
- Acute cardiac symptoms: chest pain, newly occurring shortness of breath or palpitations should be assessed before working on the breath.
- Pregnancy: exercises with breath holding or hyperventilation are not appropriate here.
- Severe trauma related disorder: interoception can itself be distressing. Getting started belongs in therapeutic support.
- Hyperventilation and cold breathing techniques: they do not belong in unsupervised self practice, especially not in water.
- Known epilepsy or a previous seizure: this applies here in particular, because hyperventilation can trigger seizures and is used in neurology as a provocation method for exactly that reason.
Dizziness, tingling in the hands or around the mouth and a feeling of tightness can be signs that you are breathing too much or too fast. Stop the exercise and continue breathing normally. Usually this settles within a few minutes. If it does not stop, if your vision goes black or if the tightness in your chest remains, this is no longer a matter for the exercise, then have it assessed medically. With severe chest pain, severe shortness of breath or loss of consciousness, call the emergency number 112.
And the most important sentence: if a thyroid disorder, iron deficiency, a cardiac arrhythmia, an anxiety disorder, a depression or a sleep related breathing disorder such as sleep apnoea sits behind the inner restlessness, then the appropriate diagnostics are needed. Especially with snoring, observed pauses in breathing or daytime sleepiness, sleep apnoea should be assessed before you work on your breathing. The breath changes regulation. It does not replace a work up of the cause.
One note that belongs here: if you are in an acute crisis or have thoughts of taking your own life, breathwork is not the right place. In Germany the Telefonseelsorge can be reached free of charge around the clock on 0800 111 0 111 and 0800 111 0 222. In an emergency call 112.
Conventional medical assessment has its firm place here and is the first step. What an integrative perspective can add is the additional question about the autonomic state. It is not part of the standard programme of a work up, and it takes time. In my experience, both together give the more complete picture.
Frequently asked questions about breathing and the nervous system
How can I calm my nervous system with breathing?
The most important lever is an exhalation that lasts longer than the inhalation. While you breathe out, the influence of the vagus nerve on the heart's pacemaker increases and the heart slows down for a moment. While you breathe in, the opposite happens.
If you lengthen the exhalation, you shift the ratio towards the parasympathetic side. A simple starting point is around six breaths per minute, which means roughly four seconds in and six seconds out. Studies show that vagally mediated heart rate variability rises during this. What matters is regularity, not perfection.
Why does a long exhalation calm you down rather than a deep inhalation?
For the autonomic nervous system, inhalation and exhalation are two different states. During inhalation the vagal brake on the heart is briefly released and heart rate rises. During exhalation the vagal influence returns and heart rate falls. This alternation is called respiratory sinus arrhythmia.
A review in Frontiers in Physiology additionally describes how the exhalation stimulates the baroreceptors via a short rise in blood pressure, which can strengthen the parasympathetic output to the heart. Deep inhalation alone, without the exhalation becoming longer, does not use this time window. In the Stanford study, the variant with an emphasised exhalation did better than the one with an emphasised inhalation. That deep inhalation increases tension is therefore not shown, it just appears to bring less.
What is heart rate variability and what does it say about my stress?
Heart rate variability, or HRV for short, describes the small fluctuations in the intervals between two heartbeats. A healthy heart does not beat like a metronome. This fluctuation arises to a large extent through the vagus nerve.
High vagally mediated HRV is regarded as a sign that your system can move flexibly between tension and relaxation. A meta-analysis by Thayer and colleagues linked HRV with activity in the amygdala and the ventromedial prefrontal cortex. Important: HRV is not a diagnostic value and varies considerably with age, sleep, alcohol and daily form. Compare it with yourself, not with others.
How many breaths per minute are ideal for calming down?
Research circles around roughly six breaths per minute, which corresponds to about 0.1 hertz. At this frequency, breathing, blood pressure waves and heartbeat swing in a shared rhythm, which is described as resonance.
A study in 75 athletes found, however, that all tested frequencies from five to seven breaths per minute increased cardiac vagal activity compared with spontaneous breathing. So you do not have to hit an exact number. Slower than your everyday breath is already the decisive step.
How long do I have to breathe before something changes?
Acutely quite fast, in the long run it takes repetition. In a study with 59 participants, vagally mediated heart rate variability rose during a five minute session already. Longer sessions of ten, fifteen or twenty minutes brought no additional effect on this measure.
For the psychological effect the data look different. In a randomised Stanford study over one month, mood improved step by step across the weeks with five minutes of daily practice. The effect therefore seems to depend less on the length of a single session than on how often you practise.
What is the difference between box breathing and breathing with a long exhalation?
Box breathing works with equally long phases of inhaling, holding, exhaling and holding. Exhalation focused breathing, by contrast, deliberately lengthens the exhalation, often with a short second inhalation before it.
In the randomised Stanford study from 2023, both forms were compared with mindfulness meditation. The exhalation focused variant showed the clearest improvement in mood and the strongest reduction in respiratory rate. That does not mean box breathing is useless. It suggests that emphasising the exhalation physiologically takes the more direct route into the parasympathetic system.
Is nasal breathing better than mouth breathing?
There are good arguments for it where the nervous system is concerned. A paper in the Journal of Neuroscience used intracranial recordings in people with epilepsy to show that natural breathing synchronises electrical activity in the olfactory cortex, the amygdala and the hippocampus.
This coupling became markedly weaker when breathing came through the mouth instead of the nose. The effect depended on nasal airflow itself. What was measured there is a timing of brain activity, not a calming effect. I still recommend nasal breathing, because it makes the breath slower and more even by itself. With a blocked nose, mouth breathing is of course fine, and the rest of the mechanism is still there.
How solid is the evidence on breathing exercises really?
Decent, but not spectacular, and that is exactly the honest answer. A meta-analysis of randomised trials in Scientific Reports pooled 12 studies with 785 adults and found a small to moderate effect size of g = -0.35 for self reported stress. For anxiety it was -0.32, for depressive symptoms -0.40.
The authors themselves urged caution and pointed to the moderate risk of bias in the included studies. For HRV biofeedback, that is slow breathing with feedback of the heart data, the effect sizes are larger. Breathwork is therefore a sensible and easily accessible building block, but not a substitute for treatment.
Can slow breathing influence blood pressure?
There is data on this. In a controlled study in Hypertension from 2005, controlled breathing at six breaths per minute in 20 people with essential hypertension lowered systolic pressure from 149.7 to 141.1 millimetres of mercury and diastolic pressure from 82.7 to 77.8. At the same time baroreceptor sensitivity increased.
That was a measurement taken while seated during the exercise, not a long term therapy. Blood pressure medication should therefore never be changed on your own. Always discuss this with the physician who knows your values.
Who should be cautious with slow breathing exercises?
Caution is advised with panic disorder involving a tendency to hyperventilate, with poorly controlled asthma, with acute cardiac symptoms, during pregnancy where breath holding exercises are involved, and with severe trauma related disorders, where interoception itself can be distressing. With known epilepsy or a previous seizure, hyperventilation and breath holding techniques do not belong in self practice, because hyperventilation can trigger seizures.
Exercises with hyperventilation or long breath holds do not belong in unsupervised self practice anyway. If dizziness, tingling in the hands or anxiety occur during practice, stop and continue breathing normally. Palpitations, chest pain or shortness of breath without an identifiable trigger should be assessed medically before you work on your breathing.
Does breathwork replace therapy or medication?
No. Breathwork is a tool for regulation, not a treatment for a disease. It can usefully accompany psychotherapy, a medical work up or drug treatment, but it cannot replace them.
If a thyroid disorder, iron deficiency, a cardiac arrhythmia, an anxiety disorder, a depression or a sleep related breathing disorder such as sleep apnoea sits behind the inner restlessness, the appropriate diagnostics are needed. The breath changes regulation, not the cause. Both together are usually the better path than either one alone.
Why do I sometimes feel more restless during practice rather than less?
This is more common than many people think, and it is not a sign that you are doing it wrong. If your system has been under constant current for a long time, stillness feels unfamiliar at first. As soon as the outer distraction falls away, the inner tension becomes noticeable.
In some people attention also turns strongly towards their own body, and this inward sensing can amplify anxiety. A very short start of one to two minutes then makes sense, with open eyes, and rather while walking than lying down. If the restlessness persists or grows, that is a reason to look at it together with someone.
Where this topic connects with others
The autonomic state is not an isolated topic. It shows up again in almost every other area I see in my practice. Here are the connections that matter most to me.
Breathing and the vagus nerve
Exhalation, heart rate variability, parasympathetic system
this articleThe vagus nerve in burnout
Stress regulation, what actually reaches the vagus
Burnout
HPA axis, cortisol profile, the neurobiology of exhaustion
Awake at 3 in the morning
Cortisol, the HPA axis and the organ clock myth
Trouble falling asleep
When the nervous system does not power down in the evening
Sleep disorders
The map of causes behind poor sleep
More articles from the Guide to Nature's Forces
- Forest bathing (Shinrin-Yoku): what happens in the body when we go into the woods
- Sauna and the heart: how often is healthy and when is caution needed?
- Ice bathing for beginners: getting started without overtaxing the body
- How much sun does the body need? Between fear of skin cancer and deficiency
- Vitamin D deficiency: why the sun is not enough in winter
- See all articles in the Guide to Nature's Forces
Scientific sources
- Russo MA, Santarelli DM, O'Rourke D. The physiological effects of slow breathing in the healthy human. Breathe (Sheff). 2017;13(4):298-309. DOI: 10.1183/20734735.009817 [Review, human]
- Noble DJ, Hochman S. Hypothesis: Pulmonary Afferent Activity Patterns During Slow, Deep Breathing Contribute to the Neural Induction of Physiological Relaxation. Front Physiol. 2019;10:1176. DOI: 10.3389/fphys.2019.01176 [Mechanistic review, hypothesis]
- Balban MY, Neri E, Kogon MM, Weed L, Nouriani B, Jo B, Holl G, Zeitzer JM, Spiegel D, Huberman AD. Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Rep Med. 2023;4(1):100895. DOI: 10.1016/j.xcrm.2022.100895 [RCT, n=114, 4 arms, 1 month]
- Telles S, Gupta A, Sharma SK, Balkrishna A. Volitionally Regulated Breathing with Prolonged Expiration Influences Food Craving and Impulsivity. Complement Med Res. 2024;31(4):376-389. DOI: 10.1159/000539618 [RCT, n=40]
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