In the world of exercise and yoga there are many misconceptions about the topic of breathing. The main points in this blog are :
- If you are doing specific breathing exercises you will have a better physiological result if you actually breathe less than normal
- The safest and most effective way to breathe for most people during exercise is with natural breathing
Increasing your carbon dioxide levels can be good for you
There are many benefits of learning how to use all the muscles of breathing and to learn to breathe in several different ways that I am going to discuss with you another time. However, when a person is in peak fitness and in the more advanced stages of yoga, it is the art of breathing a bit less than normal (mild hypoventilation), relative to the physical activity you are engaged in, that gives you the most physiological benefits. The less air you breathe every minute, the more you will build up carbon dioxide inside your body. Contrary to popular belief, carbon dioxide has many benefits inside your body. Carbon dioxide, which builds up inside you by breathing less than normal (hypoventilation) in every day life and also by exercising without over-breathing, helps to:
- bring more blood to your brain and heart (vasodilation)
- allow more oxygen to enter your body via your lungs (bronchodilation)
- increase oxygen uptake into your cells, which can increase your energy levels to 18 times as much
- calm your nervous system and reduce stress
- increase digestion of food by stimulating hydrochloric acid levels
- reduce your appetite for heavy, processed and acidic food
Relaxed abdominal breathing is the most beneficial breathing for most people in most cases
For a beginner, the best way to get the benefits of the build-up of carbon dioxide is to try to maintain natural breathing (relaxed abdominal breathing) as much as possible and in as many activities as you can. What I am saying here is that it is good to rest in a healthy posture (sitting, standing or lying) and breath minimally and naturally, and it is also good to exercise hard without forcing yourself to breathe more than you need to. You can experience some undesirable side-effects if you breathe more than your body needs to both while at rest or during exercise.
Natural breathing at rest has three fundamental properties:
1. Inhalation is diaphragmatic (abdominal)
2. Exhalation is passive (does not require additional muscle activity)
3. The amount of breathing is minimal (no more than you need at that time)
If you are exercising or doing physical activity, then it is normal to increase your breathing. However, if you are breathing naturally, the inhalation should at least begin in the abdomen, then it may also go to the chest. Ideally the exhalation is still passive, although if you are exercising really hard you may need to use extra muscles to breathe out faster (for best health results this intensity of exercise should not practiced more than about 10% of the total exercise time), and you should still not breathe more than you feel you need to during those times.
For more advanced practitioners of breath-control exercises there are many things one can do with breathing that can increase carbon dioxide once the body is adequately prepared. Very slow breathing of up to 30 seconds inhale and 30 seconds exhale, and holding the breath are two of these ways. In the graph below showing time on the horizontal axis and levels of exhaled carbon dioxide (CO2) on the vertical axis, you can see how my exhaled carbon dioxide levels (which are generally elevated if you are in good health) increased when I breathed less than normal and decreased when I breathed more than normal: I followed my period of increased breathing by not breathing at all for a few minutes. This left me with the highest level of carbon dioxide during my final period of natural breathing and also left me with increased levels of energy and a very peaceful state of wellbeing.

Most people get the best results by simply breathing naturally during posture, movement and exercise:
It is best for most people (until they are very experienced) to practice posture and movement separate to specific breath-control. It is difficult for most people to do more than one thing at once while each is still being learnt. What tends to happen when people try to learn posture and breathing at the same time is that either the posture or the breathing is compromised. Compromising the posture can damage muscles, ligaments or joints. Compromising breathing could lead to over-tension, over-stress back problems, headaches, problems with digestion immunity and your reproductive system as well as a host of other problems.
The Benefits of Diaphragmatic (Abdominal) Breathing:
The best way to breathe is Diaphragmatically. This is because the diaphragm is a key controller of the Autonomic (Automatic) Nervous System.
The Autonomic Nervous System has 3 parts:
- The Sympathetic Nervous System – This regulates the Fight or Flight Response. So it prepares the body for anticipated danger or conflict. When stimulated it causes Heart Rate and Blood Pressure Increase.
- The Parasympathetic Nervous System – This is the Relaxation – Recovery System. When stimulated it causes Heart Rate and Blood Pressure Decrease.
- The Enteric Nervous System – This system is the link between the Gut and the Brain. It is also oftenl called the “Gut Brain”. There is more nervous tissue in the Intestinal Region to do with the enteric nervous system than in the Spinal Cord. Also there is more nervous tissue around the area of the Intestines than in a cat’s brain. The Enteric nervous system regulates digestive activity. It is located in the sheaths of tissue lining in the Oesophagus, Stomach, Small Intestine and Colon. It is considered a single entity it is a network of neurons, neurotransmitters, and proteins
When the diaphragm is being used correctly the activities of the autonomic nervous system are more likely to be in balance.
To Practice Diaphragmatic Inhalations:
Here is a simple sequence of practice will be the following eight types of inhalations. All but two (exercises 4 and 5) are either purely diaphragmatic or begin with diaphragmatic breathing:
- 1a. Supine relaxed abdominal (diaphragmatic) natural breathing
- 1b. Seated relaxed abdominal (diaphragmatic) natural breathing (not shown in the figures below)
- 2. Supine enhanced abdominal (diaphragmatic) breathing
- 3. Seated enhanced abdominal (diaphragmatic) breathing
- 4. Seated chest (thoracic) breathing
- 5. Supine chest (thoracic) breathing
- 6. Seated complete (abdominal then chest) breathing
- 7. Supine complete (abdominal then chest) breathing
Each practice can be done with a passive exhalation (through the elastic recoil of the muscles of breathing) or with the assistance of muscles of breathing.
If you wish to learn more about breathing you can join our 17 session online video course on simple breath-control for everyone that can help you to calm you mind, give you lots of energy, help you sleep better and help to relieve and/or prevent back and neck pain.
Great article!! Very helpful, reaping the benefits already.
I unfortunately know of someone who took this to the next level. He inhaled CO2 from a tank thinking that the “increased” level of CO2 would energize him and maximize his strength- it instead killed him. He essentially inhaled so much CO2 that it displaced his O2 level in his blood.
Hi Linda – thanks for you comment – very interesting but sad at the same time – wow – how crazy is that – it is so important to very gradually adapt to changes in internal pH or changes in carbon di-oxide levels in the body. To do this the way he did is so dangerous obviously. This is why I teach people how re-establish the natural breathing we had as children. To tamper with your internal physiology is potentially dangerous for sure. And any changes have be done slowly and with the guidance of someone who really knows what they are teaching. There are many people in the world today who are teaching breathing techniques that are potentially very dangerous in the untrained hands – there is no such thing as a wrong exercise in my books but you have to be ready for it and many people in the world today are teaching potentially dangerous breathing of ether hyperventilation or hypoventilation or breath retentions with muscle activations that can radically alter internal pressures, to people who are not ready for them.
Hi Simon,
What are the indicators of mal practice in breathing technique?
Thanks
HI Estaban – sorry to not see your comment till now.
Indicators of malpractice in a breathing technique will be things like feeling stress or tension. Less energy or emotional catharsis after practice and hunger. These are the things that indicate that the practice of breathing was not really ideal I think
Hello Simon,
As a yoga teacher, I have been wondering for a long time about the pH of the body’s tissues or of the blood when holding the breath in AND when holding the breath out.
What are the physical & chemical differences produced between both inhalation & exhalation?
Also, at what specific part of Pranayama is the oxygen released from the red blood cells ?
And, does retaining the inhalation somehow “ squeeze “ the oxygen molecule within the air of the lungs into the blood ?
Thank you so much for sharing yr knowledge & wisdom, and for helping empower others.
Sincerely, Julie
hi Julie – thanks for your comment – my apologies – for some reason I didn’t see it till now.
It is very difficult to ascertain the true pH of the body. Blood pH is not a good indicator because it will be constantly buffered by the body systems to always be between ideally 7.35 and 7.45. If this is not the case then people will feel sick. The intracellular pH is much harder to measure. But that would give a more true indication of what’s going on. The answer to your question is difficult and I could write for a long time about it but it gets confusing without getting very technical. Also, I don’t think these things have been very well studied on a chemical level are such. There are some papers and have done some research myself but the results are often inconclusive. Results will vary from one person to the next and for one day to the next I find. And it is all affected by diet and lifestyle and the external environment.
On a physical level however there is a lot going on that is easier to talk about.
For example, if you breathe with your diaphragm then the diaphragm sends a neurological signal to the muscles of forced abdominal exploration to become reciprocally relaxed. This will increase the mobility of the spine reduce tension in the trunk and often reduce back pain. Simile breathing into the chest for most people is usually associated with the stress response and the weakening of the trunk muscles.
Oxygen is released from the red blood cells at such a time when the carbon dioxide levels are sufficiently high and that will depend on how much you’ve been breathing and how much you’ve been doing at the time.
With respect to inhalation, it is not so much the part of the breathing cycle that affects oxygen transfer from the lungs to the blood but again it is rather the level of carbon dioxide that will allow Broncodilation. Carbon dioxide has the effect of opening the bronchial tubes enough to allow the transfer of oxygen from the lungs to the blood.
These are the sorts of things that I Address on my membership site. There you can ask me questions and I usually do a video response once a week to answer people’s questions. Thank you so much for your interest. Best wishes, Simon
I have to ask what place do breath holds have, when we can Exhale longer than we inhale to increase our CO2 in the lungs?
Hi Nade, Thank you for your comment.
This is a complex question which requires a long complex answer. In short, natural breathing is the simplest way of doing any practice. However the more you can learn to function at a high level while breathing as little as possible the better. Natural breathing offers this to a certain extent, but breath-holding could potentially give a better result. The only problem is that breath-holding has a risk of pressure changes that can adversely affect the body. If you hold the breath in, especially, this can cause increased intracranial pressure that has the associated risks of headache and perhaps even stroke. If you hold the breath out then there are some physical and physiological effects as well, such as dizziness, but the most significant limitation is that the lack of air makes it very difficult for people to do that for any length of time. Breath-holding does have a significant place in a more advanced practice but it is not really suitable for most beginners.
I have noticed that you don’t recommend practicing long slow breathing in the asana practice and to use relaxed breathing. Would you have someone working towards slow breathing in the asana over time?
This is how I have been taught and practice my asanas with slow conscious breath so am interested to hear your thoughts on this.
hi Kim – Yes indeed – restoring naturally breathing is a first step only – but it is one that many people miss! – I use long slow breathing in my practice and many other types of breath control in my practice. But I tend to only do it once I feel very adept at the practise I’m doing on a physical level. I’m very open to have people progress from natural breathing if they have already established themselves in the activity they are doing, whether it’s a stationary posture or dynamic movement. Also, it is important to appreciate the minute ventilation factor. Also, it is important to appreciate the minute ventilation factor. Many people think that they are doing long slow breathing but in fact, they are still hyperventilating in comparison to natural breathing. If a posture is fairly passive and does not require any more muscular activation than sitting up straight for meditation then you don’t need to have more the equivalent of about one full breath per minute in which case 30 seconds inhale and 30 seconds exhale is an appropriate amount of Long slow breathing. Obviously, if the practice is more physically challenging and requires more energy then you can breathe more. In my observation of many students of the decades I have seen that most people will get a better result physiologically if they breathe naturally, but there are a few who can progress past that point and I love working with those people and I love practising like this myself.