In 2017, a team at Stanford went looking for the place where breathing and mood meet. They found it in mice: a cluster of about 175 neurons in the brainstem's breathing rhythm centre, wired straight into the locus coeruleus, a small region involved in attention, arousal and panic.
Then they removed those neurons. The mice went on breathing perfectly normally. They just spent more of their time calm, and less of it worked up. Same lungs, less drama.
That is the wiring behind something you already half know. Your heart, your digestion and your hormones run without asking you. Breathing runs without asking too, but of the four, it is the one you can take over by hand, whenever you like. And what you change does not stay in the lungs.
That is how breathing affects your emotional state. It is also what makes it so easy to misuse.
It runs both ways
Every feeling has a breathing pattern of its own, and the pattern works in reverse.
In 2002, a team in Belgium asked people to call up joy, anger, fear or sadness and to describe the breathing that went with each. The patterns they described matched what had been recorded in the lab, were much the same from one person to the next, and were clearly different for each feeling.
Then they turned it round. A second group was given breathing instructions built from those patterns, with a cover story so nobody could guess the point. Each pattern brought on its own feeling. Act the breath, get the feeling.
So the breath is not only a read-out of how you feel. It is a way in.
The language got there first. "Spirit" comes from the Latin spīritus, breath, from spīrō, to breathe, the same root as inspire, respire and transpire. To inspire someone once meant, quite literally, to breathe into them.
The breath out and your heart
Your heart does not beat at a fixed rate. It speeds up a little every time you breathe in and slows every time you breathe out, slowest at the very end of the breath out. It is called sinus arrhythmia, and in a healthy heart it is normal. An irregular heartbeat as a sign of health. Bodies are odd.
The brake is the vagus nerve, the longest nerve of the autonomic nervous system, the part of you that runs the body without asking. On the breath in, it eases off. On the breath out, it presses.
That is why the oldest breathing advice is to make the breath out longer than the breath in. You are leaning on the brake a little longer each time. No counting needed. Let the breath out take its time, and do not cut it short.
Six a minute
At rest, a healthy adult takes about 12 to 15 breaths a minute, and the breath out is already a little longer than the breath in, roughly two seconds in and three out. Six a minute is about half that pace.
In 2001, the BMJ published a test of the rosary.
Twenty-three adults in Florence and Pavia recited the Ave Maria in Latin, and, in another session, a yoga mantra. Both slowed their breathing to about six breaths a minute. At that pace, the natural rise and fall of their heart rate grew strong and fell into step with their breathing, and the reflex that steadies blood pressure grew more sensitive.
The same team later took the pace to people with high blood pressure. In 20 of them, breathing at six a minute lowered it in a single sitting, from about 150/83 to about 141/78, and sharpened the same reflex. One sitting is not a treatment. It does show how directly the breath reaches the blood vessels.
Two traditions, one from Rome and one from India, had landed on the same slow breath by different routes. Neither was measuring anything. They found the pace by feel. Rome and India, agreeing on something.
India had written breath control down long before. Pranayama appears in the Upanishads and the Bhagavad Gita, and in Patanjali's Yoga Sutras it is the fourth of the eight limbs of yoga, offered as a way of steadying the mind. Prana means breath.
Singing does the same job, because a song decides when you breathe. When 18-year-olds in Sweden sang a slow mantra together, breathing only between phrases, their hearts began to speed up and slow down at the same time. A choir is a group breathing exercise with better music.
The nose
Your nose is more than a way in for air. How to Boost Energy Levels Naturally, linked below, has what it does that the mouth cannot: the warming, the filtering, the nitric oxide, and why taping your mouth shut at night does not hold up. For the long history of all this, James Nestor's is a readable tour, though it is keener on mouth tape than the evidence is.
It also takes turns. One nostril does more of the work while the other partly closes, and they swap over, on average every two and a half hours, run by the same automatic nervous system that runs your heart. It was first described in 1895, by Richard Kayser in Germany.
There is one more reason to keep your mouth closed, and it is in the brain. In 2016, a team in Chicago recorded the brains of people who already had electrodes in place for epilepsy. As they breathed through the nose, the rhythm of the breath set the rhythm of the amygdala, the brain's fear centre, and the hippocampus, its memory centre. When they switched to breathing through the mouth, the effect faded. In healthy volunteers, the point they had reached in the breath changed how well they picked out a frightened face and how well they remembered what they had seen.
So nose breathing at rest is not a technique. It is the baseline. If your nose is blocked most of the time, Natural Sinus Relief: What Works, and What Makes It Worse has what clears it, and a squeeze bottle such as the NeilMed is the place to start.
What a sigh is for
You sigh every few minutes without noticing, and not because you are sad. Ordinary breathing lets some of the tiny air sacs in your lungs slump shut, and a sigh, a breath on top of a breath, reinflates them. You sigh more under stress, and when oxygen runs short.
In 2016, the team that mapped the sigh in mice found it is run by about 200 neurons in the same breathing centre, and suggested the circuit may take in emotional signals as well as physical ones. Relief and tiredness come out as the same breath for a reason.
Relief especially. In three experiments in Belgium, people put through a loud noise, or told to expect one, sighed more when it ended, or when they learned it would not come, than during the stress itself. The sigh tends to arrive after the trouble, not during it.
You can do it on purpose: breathe in through the nose, top it up with a second short sniff, then let it all go, slowly. Breaking Free from Low Moods: Powerful Strategies to Reset Your Mind and Energy has the month of daily breathing in which a long, slow breath out lifted mood more than meditation did.
Too much air
Breathing faster and harder does not get more of anything useful into you. It blows off carbon dioxide, and too little of it brings dizziness, headache, weakness, tingling in the lips, hands or feet, and sometimes fainting.
That light-headed, pins-and-needles feeling is part of a panic attack. It is also what some breathwork classes produce on purpose and sell as a breakthrough. It is your blood chemistry complaining. If a technique leaves you dizzy or tingling, stop, and breathe normally. Emergency Stress Relief, linked below, has the slow breathing that eased panic, and why the paper bag is best left alone.
Wim Hof
The most famous fast-breathing method has a real result behind it, and a warning that comes with it.
In 2014, 12 men spent ten days learning Wim Hof's method: rounds of deliberate overbreathing followed by holding the breath, cold exposure, and meditation. Then they, and 12 men who had not trained, were injected with a bacterial toxin that brings on flu-like symptoms. The trained men had far more adrenaline in their blood, less inflammation and fewer symptoms. Ten days of training against a dose of bacteria. Not a bad trade. Two systems thought to run entirely on their own, the stress response and the immune response, had been moved on purpose.
Now the warning. Overbreathing before holding your breath lowers the carbon dioxide that would normally make you desperate to breathe, and in water that can mean blacking out without warning. Four practitioners drowned in 2015 and 2016, and their relatives suspected the breathing exercises. The team behind the 2014 test had already warned Hof against making health claims.
If you try it, do it sitting or lying down, on dry land, and never in or near water.
Why some feelings last
How long does a feeling last? A popular answer is about 90 seconds, after which it is gone unless you restart it. That number comes from a memoir, not a measurement. Neat numbers are like that.
When a team in Belgium asked people to recall recent feelings and say how long each one lasted, the answer depended on the feeling. Out of 27, sadness lasted longest. Shame, surprise, fear, disgust, boredom, irritation and relief were among the shortest. What made a feeling last was no mystery: the event mattered to them, and they kept going back over it.
Which leaves the part worth keeping. The feeling is not what persists. Going back to it is. A slow breath out will not switch a feeling off. It can give you a moment before you go back over it again.
Crying
Crying gets a bad press, and it may be one of the body's own ways of calming down. A 2014 review set out how crying could soothe through the calming branch of the nervous system. The findings are mixed: in some, people felt better afterwards, and in others they did not. A good cry is not a cure. It is not a failure either.
Calm for what?
Here is where breathwork goes wrong, and it is not the technique. It is the use.
A slow breath out is a fine way to keep an argument from going badly. It is a poor way to keep putting up with something that should change. If the anxiety is about a job you cannot stand, breathing well will make you better at standing it. The job stays the same. You will just be very relaxed about hating it.
Used like that, breathing is a volume knob for a signal you should be listening to. The better use is the opposite: turn the noise down far enough to hear what the feeling is about, and then do something about it. Calmer, yes, but calmer in the service of something.
What the evidence says
Is any of this more than a nice feeling? When 12 randomised tests with 785 adults were pooled in 2023, breathwork lowered stress by a small to medium amount compared with groups that did not do it. Anxiety and low mood, across 20 and 18 tests, moved by a similar amount. Most of the tests carried some risk of bias.
Training with a read-out did better. Across 24 sets of findings with 484 people, practising slow breathing while watching a live display of the heart's rhythm went with a large drop in stress and anxiety, though the authors want better-controlled tests before anyone gets excited.
So it is real, usually modest, and not magic.
The practice
None of this needs a mat, an app or a timer.
Check the whole breath. Breathe in until the breath is genuinely finished, pause, then breathe out until that is finished too, and pause again. Notice which end you want to cut short.
Watch it over a bad email. Next time something unwelcome lands on your screen, check whether you are still breathing. If you are holding it, let it out slowly. The email will still be there. So will you.
Start during exercise. Notice whether you hold your breath on the hard part, or switch to your mouth when you walk fast. It is the same habit you fall into under pressure, and nothing hangs on it.
Read it before you sit. If you meditate, check your breath before you start. Short and high in the chest tells you what state you are arriving in.
Slow it down at bedtime. When 14 people with insomnia practised slow breathing, about six breaths a minute, before going to sleep, they fell asleep faster, woke less and spent more of the night asleep. It was a small test, and the breath out costs nothing.
One breath before you answer. Someone says something in a meeting that lands hard. Your chest tightens, and your reply is forming before they have finished. One slow breath out before you speak puts a gap between what you heard and what you say.
Back to the brainstem
Those 175 neurons in a mouse's brainstem make one thing plain: breath and mood are not two systems that happen to meet. They share wiring. You cannot reach the wiring. You can reach the breath.
Use it to listen, not only to settle.
Next time something lands hard, breathe out once, slowly, before you answer.
Heart pounding right now? Emergency Stress Relief: What to Do When You're Completely Overwhelmed — what works when you are too wound up to follow ordinary advice: the sigh, cold water on the face, and the plan to write while you are calm.
Tired, and breathing through your mouth? How to Boost Energy Levels Naturally: Little-Known Remedies That Actually Work — what your nose does that your mouth cannot, why the mouth tape fails, why a house plant will not save you, and where to start if you only do one thing.
Know someone who holds their breath through every email? Send them this. Then watch them check.
Tried something here, or got a question it didn't answer? Write to us at contact@allforlife.club. Your questions shape the next articles.
Disclaimer: This article is general information. For advice about your own health, talk to a qualified health professional. If a breathing exercise leaves you dizzy or tingling, stop and breathe normally. Never practise fast breathing or breath-holding in or near water. Chest pain, or breathlessness that does not ease, needs emergency help straight away.
Affiliate Disclosure: This article contains affiliate links. As an Amazon Associate, All For Life earns from qualifying purchases, at no extra cost to you. We only link to products we would recommend without the commission.
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