Most of the material summarised here, I've picked up from
https://youtube.com/c/OxygenAdvantage
Balance your autonomic nervous system
People whose nervous system is in sympathetic overdrive take longer to recover from illnesses than people who are more tilted in favour of the parasympathetic half. Breathing correctly is the best way to stay in rest repair and regeneration phase
Nose, slow and low
For someone recovering from an infection, COVID, for example. Remember these 3 things.
Nose breathing. Slow breathing. Low breathing.
Nose breathing is antiviral. Nose breathing produces nitric oxide which then works as a signal to the body that everything is going smoothly and that it is time to relax. Blood vessels widen in response to the nitric oxide, this lets more oxygen and nutrition reach your tissues, so that they can repair and rejuvenate themselves. Nose breathing and the nitric oxide produced by badal breathing both simulate the vagus nerve, which is crucial for rest, repair, regen.
Slow breathing, is when you breathe so slowly and smoothly, that the hair in your nostrils don't move.
Low breathing is making sure that most of breathing work is done by the diaphragm. When you inhale, most of the movement should be visible at the abdomen and lower chest.
Fast and hard breathing is your emergency gear. If you're breathing in that manner, the brain interprets the problems at hand, as an existential threat. There's a saber toothed tiger hunting you. And you need to get away. Survival matters. Getting sloppy isn't a concern. All that matters is keeping you alive. Your vision becomes narrow. You lose awareness of the big picture. You lose sight of strategy and all you do is, start hyper focusing on tactics which are unnecessarily wasteful, and lead to sloppiness. If that happens only once a day, it might not matter. But if you're doing it all day, every day, for decades, your going to end up compounding errors. You're going to pay an unnecessary heavy price, even as you fail.
In a crisis, you need to make sure that you're not overbreathing, technical term - hyperventilating.
It doesn't add to your performance. It usually degrades your performance. So it is always worth your while to run a breathing system check just before you go into battle. Whatever your battle might be. Whether it is operating on someone's heart, it if you're going to discuss a new bicycle purchase with your spouse. It is also worth your while to do a systems check on your breathing when you're losing a battle. When things are going wrong, or, about to go wrong or there's a possibility that they may go wrong. It is worth your while to check your breathing for 5 to 10 seconds.
In modern life, we're always lurching from one meaningless "crisis" to the next. Making sure that you're breathing right, will make sure that you win. However, more importantly, breathing right will also help you decide if the crisis you're facing is really a crisis or if it is just an overblown problem that you're creating in your own mind. It'll also help you decide whether this crisis is worth sidestepping and attacking from a different angle at a different time when the chances for success are much higher. Sometimes you'll come back to see that the problem has solved itself. Sometimes you'll move so far ahead, that the problem hobe sidestepped is no more a priority.
Teaching someone how to breathe Light/Slow/Deep (LSD) should be an international priority. Especially for the urban population that is completely out of touch with nature and with their own selves. It is a force multiplier for the individual and for society. Instead, we're teaching people how to be slaves. Ineffective ones, at that.
Control of breath, is the easiest way to learn to control your attention. There are other ways, but in my opinion, it is the easiest. If your attention is wandering, and you're being lead by your attention which is hijacked by crises manufactured by yourself or by society, you become easy to manipulate. You become cattle with a nose ring, getting dragged around by the master, unable to do what is best for yourself. You aren't even allowed to turn your head to look around and become aware of what is happening. When you're not even aware of what better options are available to you, you'll become docile and obedient. And all the effort that you put in to what you think is life, will be harnessed by the person holding your nose ring.
Changing the breath and improving sleep, as a consequence, changes your body chemistry. This makes it easier for you to start effecting positive change in your health and life in general. This is the foundation. Breath.
Flow State.
Where your mind is relaxed, but you're alert and responding with ease, to your environment. That's the goal. And the ability to get into that flow state, where there is no forced thought, is enhanced by the right breathing.
PRACTICAL TIPS
Mouth taping at night promotes nose breathing for 8 hours. That's a win right there, without any real effort required.
A mouth filled with saliva, a mouth that's not dry, indicates that your nervous system is running in parasympathetic dominance.
Give children harder food to chew on, so that their jaws develop better.
Good sleep in children, gives them a better chance to have normal brain development. The rise in autism spectrum disorders is probably linked to poor sleep and breathing among children.
Tongue needs to rest at the roof of the mouth, when not talking or eating.
Dentists need to do more to encourage nose breathing. Doctors need to do more to encourage nose breathing.
Snoring indicates poor sleep. Indicates mouth breathing.
" Big Deep breaths" are BS. You need to take appropriate breaths. That'll come with practice. Idea would be to use the bare minimum breathing required. To experience air hunger on a daily basis.
Myofunctional therapy for the tongue and the airway
- sticking out your tongue and trying to touch your chin
- sticking out your tongue and try and touch your nose
- stick out your tongue and move it from side to side 10 times
- clean the outside of your teeth with your tongue with your mouth closed 10 times in one direction 10 in the other direction. Upper and lower jaw
- stick out your tongue, take it back in and drag it along the roof of your mouth, backwards until you feel the beginning of your soft palate. End by trying to pull the back of your throat, further backwards.
Picture increasing the distance between sternum and navel
Picture increasing the distance between ribs, especially lower ribs. Front to back and side to side
Breath hold time of 25-40 seconds. 40 being the goal.
Breath hold time is measured when you're resting. Take a regular breath in. Then regular breath out, pinch your nose. And count seconds till you feel the first impulse to take a breath. When you restart taking that breath, you should find that you're still breathing relatively normally. Be honest in your self assessment.
When it comes to changing breathing, the focus has been on changing the number of breaths. But more focus needs to be given on how much you take in with each breath (you need to take less)
Air hunger is good. It'll reduce the sensitivity towards catch dioxide. This goes a long way in reducing hyperventilation. You'll know that it is working, if your mouth fills up with more saliva as you breathe slower. If you're doing it right, you'll also notice that your hands and feet stop feeling cold, or less cold. They become warmer.
Be aware of the way you breathe during different emotional states.
Animals that breathe the slowest, live the longest.
There are parallels between the philosophy of breathing and eating. Digesting what we take in is important. Instead of simply forcing in more and more, in the hope that something will fill the hunger and deficiency.
"Resonance frequency" respiratory rate- at rest, should be around 4.5 to 6.5 breaths per minute. This indicates that breathing is optimal. And with it your autonomic nervous system.
Box breathing.https://youtu.be/tEmt1Znux58
Focus on the exhalation phase for 90 seconds.
Orthodontic work- not just to straighten the teeth. Also to make sure that there is enough space in the mouth for the tongue to stay in place during rest, activity and sleep.
Mewing
Because it is a big topic on it's own, i thought it'll be easier to add a video link
https://youtu.be/Y9zhiJWs1DE
Practice breathing right, when you're not under stress, so that you're prepared to shift to proper breathing and reduce stress with the breathing technique you already know

Excellent writeup. Saving this article for multiple reading until this becomes a habit. You didnt try to complicate tbis using term "meditation".
Taking notes. This is such a good post. Thank you so much!!