Science of Breathing

Deep dive into the science of breath.

Key terms about the science of breathing

Get an introduction to the terms used in my online breathing programmes.

Bohr Effect
Nitric Oxide
Heart Rate Variability
Neurobiology of Breathing
The Vagus Nerve

Bohr Effect

Bohr Effect

Breathe Less for Better Health

Did you know that there is a direct connection between the level of carbon dioxide in your blood and the release of oxygen to your cells, tissues and organs?

Why it matters

When I discovered that Breathing Less air actually increased the amount of oxygen delivery within my body, it was a revelation to me.

No one had ever told me this and like so many other people I always presumed that the more air I breathed in the better.

Yet the science behind how our breathing works shows the opposite. We need to breathe less air to improve oxygen uptake within our bodies and to promote efficiency within our respiratory system.

This is all connected to a principle called the Bohr Effect.


The Bohr Effect was first discovered by a Danish physiologist called Christian Bohr in 1904.

It states that “The Affinity of Hemoglobin for oxygen changes depending on the level of Carbon Dioxide in your blood”.

So what does the Bohr Effect mean for you and your breathing?

In simple terms the Bohr Effect states that the higher the level of carbon dioxide in your blood the greater the release of oxygen from your haemoglobin to your cells, tissues and organs.

The opposite is also true – The lower the level of Carbon Dioxide in your blood the lower the release of oxygen to your cells, tissues and organs as the oxygen binds onto the haemoglobin to a greater degree.

A human body graph showcases science behind healthy breathing

We need a healthy level of Carbon Dioxide in our blood for optimum Oxygen to our cells, tissues and organs.

Breathing through your nose and breathing less as a habit allows you to access the Bohr Effect.

Oxygen is carried around our body by Haemoglobin. But it is not enough for the oxygen to be on the haemoglobin, we need it to leave those red blood cells and go to our cells, tissues, organs and working muscles.

Carbon Dioxide facilitates the release of oxygen from the haemoglobin.

The breathing exercises in the breathing programmes train you to have a healthier level of carbon dioxide in your blood and a greater oxygenation in your body as a result.

Nitric Oxide

Nitric Oxide

Breathe Through the Nose

Harness the gas Nitric Oxide that is produced in our paranasal sinuses. Breathing through the nose allows for the release of a gas called Nitric Oxide from our paranasal sinuses.

Why it matters

Nitric oxide is very important for cardiovascular health as when nitric oxide is depleted it can cause plaque build up in the cardiovascular system.

Through our breath it is vital to breathe through the nose to harness the benefits of Nitric oxide. Interestingly the less volume of air that we breathe through our noses the greater the release of Nitric Oxide in our bloodstreams.

In my Breathing programmes I focus on guiding my clients to establish light, slow, calm and gentle breathing through their noses as a habit. This way of breathing naturally encourages the greatest release of Nitric Oxide in your body.

There are many benefits of Nitric Oxide. Nitric Oxide plays an anti-inflammatory role in the arteries, it is a vasodilator so it decreases blood pressure and improves blood flow to the organs.

This benefit of Nitric Oxide was used to great effect in the creation of the drug viagra, which helps with erectile dysfunction by increasing the levels of nitric oxide in the body and thus improving blood flow.


Three men called Louis Ignarro, Robert Furchgott and Ferid Murad won the Nobel Prize for Medicine ( Science) in 1998 for discovering the many benefits of Nitric Oxide in the human body. Prior to that it was commonly thought that Nitric Oxide was a poisonous gas that had no positive functions in the body.

As a result of these men winning the Nobel Prize Nitric Oxide has been widely researched in the last 20 years or more.

One of the great discoveries coming out of this research was that Nitric Oxide functions as a signalling molecule to maintain normal bodily functions and to the cardiovascular system.


Nitric Oxide has been used in hospitals in the fight against Covid-19.

Nitric Oxide has been used in hospitals in the treatment of seriously ill Covid-19 patients.

Nitric Oxide was administered to these patients as it has Anti- Viral and Anti-Bacterial properties.

A man with asthma trying to breathe healthy

There has never been a more important time to harness this gas that is produced naturally by nose breathing!

The simplest way to access the benefits of Nitric Oxide is to learn to breathe through your nose as a habit and learn to breathe calmly, gently and slowly.

We breathe on average 20,000 to 30,000 times a day so each breath you take is an opportunity to harness this amazing gas in your body and improve your health.

Lungs model showcase science behind healthy breathing

Heart Rate Variability

Heart rate chart showcase science behind healthy breathing

Many people in the modern world are breathing in the “fight or flight“ manner without realising that they are doing it.

In general an overactive sympathetic state in our nervous system causes a decrease in our Heart Rate Variability.

When we are in the parasympathetic state our breathing tends to Slow Down, we tend to breathe more gently through our noses and our breathing is calm and under control.

Our breathing in the parasympathetic state is less noticeable, more regular and we breathe using our diaphragm or tummy breathing activating genuine deep breathing.

The parasympathetic state is also known as the rest and digest state for our bodies.

It is when we are most relaxed that the parasympathetic nervous system is activated.

During this state Acetylcholine is released and this causes our heart rate to slow down and importantly, increase the intervals between our heart beats.

Linked to wellbeing

Your habits

Heart Rate Variability

Breathing from the Heart

Heart Rate Variability or HRV is a marker of how healthy we are. Did you know that you can influence your Heart Rate Variability by changing your breathing patterns and habits?

How you Breathe and your Breathing patterns directly affect your heart rate Variability.

There is a natural variability in the space between your heart beats and this variability says a lot about how healthy you are!

This is known as Heart Rate Variability or HRV for short.

Your Heart Rate Variability is a measurement of the balance between the Sympathetic and the Parasympathetic Nervous System. These are the 2 branches of the autonomic nervous systems.

The sympathetic nervous system is also known as the fight or flight response.

When we are in that state of fight or flight our breathing tends to come from our upper chest, we tend to breathe through our mouths and our breathing is fast or rapid.

In this state our breathing is often very noticeable, irregular and erratic.

This way of breathing is a natural response in an emergency situation; it is when this way of breathing becomes our habitual way of breathing that it is detrimental to our health and wellbeing.

Heart model with graphs about high blood pressure


Tongue is important for healthy breathing


The tongue plays a vital role in our health and wellbeing. Many people do not know that the tongue is actually an organ and not simply a muscle in our mouth. The position of our tongue in our mouth is very important. The correct position of the tongues is resting on the roof of our mouths with the tip of the tongue behind the two front teeth.

When we are asleep the tongue plays a very important role in a deep, restful sleep.

If our tongue is not sitting in the correct position during sleep it can block our airway.

For many people this is made worse as their jaws have not developed to their full potential and there is not enough room to accommodate the tongue correctly.

This can have detrimental effects on our breathing during sleep and on our health and wellbeing.

When we are in the deeper stages of sleep our muscles relax and our tongue can drop back and block our airway causing us to hold our breath and have episodes of Sleep Apnea.

Neurobiology of Breathing


Breathing Impacts Brain Health

According to Jack Feldman, professor of Neurobiology at UCLA “ Breathing underlies all aspects of brain function.” This is a very powerful statement to make but it makes absolute sense when we remember that our breath is the most vital process in our body and is what gives us life.

Why it matters

Our breath underlies everything we do.

In recent years there has been more and more research about how our breathing patterns and habits can affect our neurobiology. Our neurobiology, or in simple terms, the functioning of our brains is intrinsically linked to how we breathe.

In a study in Northwestern University in 2016 it was discovered that the “ Rhythm of our breathing affects memory and fear- Our breathing is not just for oxygen, it also is linked to how we behave and the functioning of our brains.”

The scientists discovered that the rhythm at which we breathe alters the electrical charge in our brains that enhances emotional judgements and memory recall.

This is fascinating from the perspective of the breathing programmes that I teach, which focus on the importance of nose breathing and also on the importance of consciously focusing on our breath.

The study showed that it really does make a difference to your brain function whether you breathe through your nose or your mouth!

I often teach young children in the classroom and the breathing programmes about the importance of nose breathing.

The study also noted improvements in memory and emotional judgements after an inhale.

When I am teaching the reduced breathing exercises I encourage clients to narrow their focus down to the next in-breath, always with the mouth closed and to allow the out breath to be passive. Each breath we take, and how we take really does matter.

Nose breathing is central to everything I teach in the breathing programmes and this study showed more reasons why nose breathing is so important to our wellbeing.

When we breathe through our nose we are more likely to be able to read emotions of fear in other people- thus allowing us to access more empathy.

A neuron in the brain explain the science of healthy breathing

When we breathe through our noses our memory and recall improves.

This study has huge implications for their ability to learn and show empathy to each other in the classrooms. It is clear that nose breathing is best for our children’s memory, learning and cognitive development.

In a study that professor Jack Feldman completed at UCLA it was discovered that the beginning of each breath is what seems like haphazard and cacophonous firing of neurons that are like members of a choir that are all singing off key.

What is truly amazing is that these many different neurons quickly synchronise to create harmony with each breath.

The researchers compared this to a choir which begins with each individual singer on their own singing off key that joins with all the other singers to create a beautiful harmonious sound.

It is clear that there is a wonderful intelligence behind each breath we take!

Brain model showcase science behind healthy breathing

The Vagus Nerve

The Vagus Nerve

Science behind Slow Breathing

The Vagus Nerve plays a vital role in the healthy functioning of our body.

Why it matters

It runs down through your body. The vagus nerve emerges from the brain and runs all the way to the abdomen. The Vagus Nerve innervates major organ systems such as the heart, lungs and the gastrointestinal tract. Interestingly most of the signalling from the Vagus Nerve is on an afferent pathway, meaning that 80 to 90 percent of the messages of the Vagus Nerve are carried from the body back to the brain and not from the brain to the body.

It has been shown that good “vagal tone” and healthy functioning on the Vagus nerve can be achieved by practicing slow breathing- ideally 5.5 to 6 breaths per minute at rest.

The Vagus Nerve interfaces with the Autonomic Nervous System. When we are stressed our body activates the Sympathetic Nervous System. If we are constantly in a stressed state the Parasympathetic Nervous System, which is the rest, digest and relaxation branch of the Autonomic Nervous System is not correctly utilised by our body. This is very detrimental to our health and wellbeing.

The stressor may have originally been psychological in nature but it can cause havoc on a physiological level in our body.

The good news is that we reverse this by changing our breathing patterns and habits.

As the Vagus Nerve mostly sends signals from the body to our brain we can greatly influence how we feel psychologically by addressing the issue on a physiological level.

A Vagus nerve model showcase science behind healthy breathing

How can we do this?

By consciously slowing our breathing down, activating the Vagus Nerve, switching our Autonomic Nervous System functioning out of the “fight or flight” Sympathetic State and into the Parasympathetic State which allows us to rest, digest, relax and heal.

So a stressor that may be the result of thoughts, worries or concerns we have can be managed by changing the physiological processes in our body into wellness and healing.

One of the most powerful means available to us to do this is to deliberately slow our breathing down and change our breathing habits consciously. The physiological changes that occur when we alter our breathing, through activation on the Vagus Nerve and improved vagal tone has direct, positive benefits on how our brains function and on how we feel.

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