Sunday, 2 June 2013

Everything I Know: Breathing

If you can't be bothered reading everything below, here's the stuff that helps you: breathe through your nose all the time and make sure you're breathing into the lower portion of your lungs. Remember that the slower you breathe the more carbon dioxide builds up and that carbon dioxide is not a waste gas, it is very useful within your body but needs to be maintained at a certain level (not causing discomfort unless you are deliberately trying to adapt to different carbon dioxide levels, such as in Buteyko breathing).

How to Breathe efficiently

This will help you specifically in dealing with stress but it has many applications and should be done constantly. The instruction to breathe in for 4 seconds and out for much longer is specifically an anti-stress tool. If you did this all the time you would more than likely become very tired, however, it is worth bearing in mind and cultivating it as a skill.

Close your mouth and press your tongue against the back of your two front teeth, breathe entirely through your nose. Make sure that you are breathing into the lower portion of your lungs. To check that you are doing this correctly, place the palm of your left hand on your belly button and your right hand on your chest. As you breathe in, notice which hand moves most. Ideally, your left hand should be pushed out by your inhale and your right hand should barely move, if at all. This should be how you should be breathing in all circumstances, apart from real danger (being chased by a lion for example). If you have a panic attack, probably the fastest way to stop the panic is by changing to this style of breathing. To get the best anti-stress results from breathing you should aim to breathe in for around 4 seconds and then breathe out for as long as is comfortable. In general, inhalations stimulate the sympathetic nervous system while exhalations stimulate the parasympathetic nervous system. Therefore, if your exhalations are longer than your inhalations you will feel much calmer. If you practise this you can get to a point where you will breathe in for 4 seconds and out for over 20 seconds. As you do this you'll notice that all of the muscles in your body become naturally inclined to relax.

Diaphragmatic breathing:

It is important to breathe into the diaphragm as this is where the highest proportion of blood vessels are within the lungs. It has been shown that the upper 7% of your lungs will only take in 4 ml of oxygen per minute whereas the lower 13% of your lungs will take in around 60 ml per minute. Also, using diaphragmatic breathing requires so much less energy to perform that it requires less than 5% of total oxygen intake. If you are over-breathing  the energy requirement goes up massively, when volunteers were told to hyperventilate on purpose they used up 30% of their oxygen intake just to breathe in this way. So by breathing into the diaphragm, you not only take up a significantly larger volume of oxygen into your blood, but you also reduce the amount of oxygen (and energy) that you waste in performing the breathing itself.

Nasal breathing:

The nose is the narrowest place in the respiratory tract, it creates a bottleneck that results in airflow being restricted before it travels into the lungs. Compared to the mouth, it requires 1.5 times the amount of energy to pull the same volume of air through the nose.

Within the nasal cavity are bony projections called turbinates  They heat and humidify air that is drawn through the nose and into the lungs. This reduces the damage that air causes to the lungs. The nose is also useful in breathing because it filters the air that is drawn into it. This takes place because there are many small hairs on the inside of the nose. This means that we take in less bacteria every time we breathe and consequently, our immune systems are less likely to become overworked. It is estimated that when these particles are caught in the nose hairs and/or mucus within the nose, that they are removed from the body within 15 minutes. However, if they travelled to the lungs they would take a few months to remove. Every time you breathe through your mouth you send these particles to your lungs and increase your chance of having a lung infection.

It is said that while breathing through your nose, if you are breathing through the right nostril you will be more inclined towards energetic pursuits, or those involving aggression. Conversely, breathing through the left nostril is associated with feelings of calm and introspection. Over the course of a day, the airflow between the nostrils will change of its own accord. You may wake up, for example, breathing through the left nostril and by midday realise that there is more air coming out of your right nostril.

In a study in which volunteers were subjected to a stress test, with some participants breathing through their mouth and the others through their nose, those who breathed nasally experienced brain wave activity that indicated greater relaxation.

Nitric oxide is also present in the nose and the slowing of air as it enter the nasal cavity allows nitric oxide to mix with the incoming air. This causes nitric oxide to be taken into the lungs where it dilates the blood vessels (bronchodilation). This allows significantly more oxygen to be taken in by these blood vessels and is very beneficial to the overall health of the organism.

Breathing through the nose is also beneficial in that it forces our breathing to slow down and as a result, our bodies follow suit. This helps us to reduce stress and think more clearly.

Nitric Oxide:

Nitric oxide (NO) is secreted into the nasal passages and is inhaled through the nose. It is effective in dilating blood vessels and also aids the lungs in the uptake of oxygen. it is produced in the walls of blood vessels and is required for the optimum functioning of every organ in the body.

Due to its vasodilatory effects, NO is useful in reducing blood pressure, increasing blood flow and treating heart-related diseases (cardiovascular diseases). This is also a reason why it is used in viagra.

In the cardiovascular system, NO reduces artery-clogging plaque from forming. In the immune system, it helps fight off infections and cancer cells. In the nervous system it helps brain cells communicate properly.

Its benefits include:

- Vasodilation / increased blood flow to tissue / reduced blood pressure
- Protecting the heart during heart attacks
- Boosting brain power / cognitive functioning
- Regulating digestion / relaxes the smooth muscles in the gastrointestinal tract
- Improving the immune system
- Re-building muscles after exercise
- Improved sexual functioning
- Aiding the liver and pancreas work more efficiently

It is produced during exercise and regulates contractility of cardiac muscle, as well as reducing heart rate.

However, as with all things in the body, nitric oxide must be produced in moderate amounts as it is a free radical, capable of damaging both pathogens and healthy cells alike.

Carbon dioxide:

Carbon dioxide is commonly referred to as a 'waste gas' from respiration. I feel that this is highly disrespectful to carbon dioxide. Your body requires a delicate balance of carbon dioxide, generally within 35 and 45 mmHg (millimetres of mercury at sea level, a pressure measurement) within the blood. If you breathe too quickly you approach the lower end of this scale and feel dizzy and if you breathe too slowly you approach the upper end of this scale and feel breathless. Most people need around 40 mmHg or above, to function normally. Below this your cells aren't getting adequate oxygen. The reason for this is illustrated by the Bohr effect. Without going into too much detail, the essence of this is that your blood cells offload their oxygen (this is desirable) around cells that are producing more carbon dioxide. Hence, if you breathe too rapidly you deplete your body of carbon dioxide and the blood cells continue to carry oxygen around the body without giving it to cells and tissues that require it. The result of hyperventilation is an impaired ability to think, among many other signs. This is primarily because the brain is suffering from oxygen deprivation (even though you are breathing rapidly and getting a lot of oxygen into the body), because your level of carbon dioxide is inadequate.

Role of CO2 in oxygen transport

Cells that are respiring more actively than others will release a lot more carbon dioxide into their external environment. This causes the dilation of blood vessels and subsequently means that more blood is able to come near tissue that has a higher metabolic rate. When the red blood cells that are carrying oxygen come into contact with this carbon dioxide they are more likely to release their oxygen. It also means that more glucose can be given to these same tissues.
When carbon dioxide increases in the blood it is converted into carbonic acid, causing a drop in the pH of the blood. This increase in acidity is what primarily results in oxygen being deposited by the red blood cells. Conversely, lower levels of carbon dioxide cause less carbonic acid to form and so less oxygen is dissociated from haemoglobin into the respiring tissue.
Thus, when we hyperventilate, we remove carbon dioxide from our bodies before it has the chance to form carbonic acid. The result is widespread hypoxia. Despite taking in much larger volumes of oxygen, this oxygen is not effectively utilised by the body. Also, this loss of carbon dioxide causes our blood vessels to constrict which means that their pressure is increased and red blood cells travel faster through them, further reducing their capability to give up oxygen. The result of this loss of acidity is called alkalosis, a reduction of hydrogen ions. This actually causes increased excitation of cells, e.g. neurons in the brain, and increases their oxygen demand. This can be considered a compensatory response in order to increase the carbon dioxide concentration within the body. However, it is worth noting that by overbreathing due to stress (over-excitability), you actually cause increased excitation and therefore increased stress over the long-term.
The effects of hypocapnia-induced hypoxia are compounded by hypoglycaemia. Due to the constriction of blood vessels mentioned earlier, the blood cells cannot adequately transport glucose to respiring tissue either. The effects of both of these deficits is particularly noticeable in the brain. People who routinely hyperventilate will feel drained, more anxious, more irritable, are more likely to suffer from insomnia and feelings of low-self esteem, vulnerability, being overwhelmed and panic. Fortunately, this particular problem is easily remedied by correct breathing.

Here is a study showing that taping the mouth can increase the end-tidal carbon dioxide in humans. This suggests that there is a higher concentration of carbon dioxide within the blood as well:

In order to understand why correct breathing doesn't come naturally to many of us we need to consider the type of lifestyle that we all live. It is primarily one of emotionally suppression and stress, both of which cause us to tense our stomach muscles and breathe into our chest. This is a manifestation of the body's fight or flight response. I think a more illustrative way of thinking of the fight or flight responses are to consider them as being a response to Anticipated Exertion. This way it becomes easier to understand why our bodies react in the way that they do. For example, if we were to undergo physical activity then our cells would greatly increase their carbon dioxide production. If our body anticipates that we will undergo physical activity then it naturally begins to breathe in a way that causes this carbon dioxide to be expelled. The problem occurs when our stressors are imaginary and we stay still. This causes us to lose carbon dioxide without producing more of it. The result is hyperventilation and strangely, increased stress.

Slow breathing

Through looking at various biofeedback techniques related to breathing (such as breathing while connected to blood pressure and heart rate monitors) I have come up with the following information:

For most people, breathing at 10 or under breaths per minute will activate the parasympathetic nervous system (a branch of the nervous system which calms us down and lets us enter a state of rest and repair). Brain waves are affected too, it has been shown via biofeedback that slow, diaphragmatic breathing increases alpha waves in the brain which are associated with a relaxed yet alert state of mind.

This form of breathing also stimulates the vagus nerve which in turn inhibits inflammation, suggesting that correct breathing reduces inflammation and that improper breathing may exacerbate it. This is significant as inflammatory disease include arthritis, colitis, ischemia, and heart attacks. Negative thinking can also trigger inflammation which may progress to depression. Therefore, breathing exercises which reduce stress and inflammation could be useful in combating depression.

Slow, diaphragmatic breathing also increases heart-rate variability, if you are stressed your heart rate will remain inside a strict boundary of around 10 beats per minute. For example, it may vary between 75 and 85 beats per minute. If you breathe more slowly this variability increases, a sign of relaxation. In some studies it has been shown that breathing 5 to 7 times per minute can increase heart-rate variability up to 35 beats per minute. This means that your heart rate may go up to 95 bpm while inhaling and drop down to 60 bpm while exhaling. Generally, the larger the heart-rate variability, the greater the effects of relaxation from the exercises.

It can also dampen pain perception too, in a study where both healthy individuals and those suffering from fibromyalgia were subjected to heat pulses on their hands, it was found that a reduced breathing rate was effective in reducing pain perception for all of the healthy volunteers, although only some of the fibromyalgia sufferers. Both groups were given the heat pulses when first breathing at a normal respiratory rate, and then following this, they breathed at 50% of the previous rate. The participants which had fibromyalgia only reported a decrease in pain perception if they also felt positive affect. Positive affect refers to an elevation in their mood, for example, feeling more happy / content / relaxed.


Hyperventilation and overbreathing essentially mean the same thing though hyperventilation is used more in medical and clinical diagnoses. They refer to a state of breathing that is faster or deeper or both in comparison to necessity. Breathing faster and deeper in response to exercise is not hyperventilation as the body is producing more CO2 and so the increased oxygen intake and CO2 removal is necessary. A measure of hyperventilation is 'minute ventilation' and refers to the volume of air that is breathed either in or out during a one minute period.

Overbreathing refers to the excessive removal of carbon dioxide leading to hypocapnia (lack of CO2). This can occur through chest breathing or diaphragmatic breathing. While diaphragmatic breathing is generally considered as the healthy option for breathing mechanics, it is not immune to the same detrimental effects of chest breathing.

When we are exercising, stressed or in some way aroused we are more likely to breathe using our chest. This is important because the way in which we breathe is highly influential towards our mood, digestion and the function of our brain and nervous system. When we are stressed but not increasing our physical movement (through exercise), we breathe using our chests in more rapid, shallow breaths. This causes more oxygen to be taken into the body, but this can only be absorbed if carbon dioxide levels are adequate. This is an anticipatory response; because our bodies are programmed to believe that if we are stressed it is because of some sort of danger or other motivation to bring about physical movement (which would increase oxygen demand in respiring tissue and consequently cause more carbon dioxide to be given out by those tissues) this means that we will automatically begin taking in more oxygen. However, this can paradoxically lead to hypoxia, the deficiency of oxygen. Our blood cells release oxygen much more readily into tissue that has higher metabolic activity (and therefore releasing more carbon dioxide). If we take in more oxygen but our cells are not respiring to an extent that creates adequate carbon dioxide to be released, then this oxygen binds to red blood cells and doesn't let go. No matter how much oxygen you have in your blood, if it doesn't want to leave your blood cells and enter your tissue, it is not beneficial and can even be harmful to you.

Chronic hyperventilation

When chronic hyperventilation occurs the body has a number of responses. Red blood cell production increases in an effort to distribute more oxygen to the capillaries. This causes the blood to thicken and consequently the heart must beat faster in order to pump this extra blood around the body. This increased strain causes physical and mental stress within you, leading to chronic low levels of anxiety. This anxiety causes your oxygen demand to further increase and your breathing to become faster and shallower. This leads to the further removal of CO2 which further diminishes your ability to absorb the oxygen which you now need more than ever. This is a major cause of stress and leads to many disruptions in general life contentment, mood and health as will be covered later. Your brain itself takes in around 20% of your total oxygen intake. When oxygen availability to the whole body drops due to inappropriate breathing, your brain experiences this and the many detrimental effects just like the rest of the body. This can lead to a decrease in serotonin and increase in cortisol (stress hormone), which causes the cycle to continue and worsen. This effect on the brain is particular noticeable to the hippocampus (a primary memory area of the brain) which is sensitive to both oxygen deprivation and higher cortisol levels.

Thoracic breathing is generally believed to stem from emotional suppression. In our Western culture it is usually encouraged that we act as though stressful situations don't bother us. This can cause us to either hold our breath or breathe irregularly which contributes to the effect created by the situation itself.

Diaphragmatic is considered to be more healthy because many small blood vessels which are instrumental in carrying oxygen to blood, reside here. With thoracic breathing these blood vessels never receive a full share of oxygenated air. This can result in shortness of breath and anxious feelings.

Breathing is perhaps the most important homeostatic mechanism in the human body and its purpose is to ensure adequate cellular oxygenation. The average human breathes between 12-20 breaths per minute, equating to 17,280 to 28,800 times per day, so if the incorrect mechanism is repeated over and over again each day it is easy to see that it will have repercussions. Thankfully, the ability of humans to take voluntary control of breathing means that we can correct our breathing mechanisms if they are causing problems with our health.

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