By Dr Raymond Lau, Chiropractor

Breathing is a natural part of human life that occurs around 20 000 times per day without any conscious thought or control. However, that doesn’t necessarily mean we are breathing optimally, it has been estimated that approximately 1/3 of the population have a breathing dysfunction affecting physical and mental health.

In the modern world, dysfunctional breathing can be brought on by stress, sedentary lifestyle, and unhealthy diets. These can then contribute to fatigue, sleep apnea, respiratory conditions, heart disease and even “poor” posture and “tight” muscles. This can be traced back to chronic over-breathing — which can have characteristics such as: mouth breathing, regular sighing throughout the day, gasping for air, noticeable breathing during rest, snoring, and early fatigue in exercise and upper chest breathing.

Take a minute to assess your own breathing and determine how many of these characteristics you display throughout the day. If you find yourself doing one or more of these, chances are you tend to over-breathe.

Over-breathing is a result of breathing more air than what our body requires. Most of us think that when we breathe, we need to get as much oxygen into our bodies as possible, which is partially correct. However, our blood oxygen saturation levels throughout the day stays relatively constant at 95-99%, assuming we aren’t holding our breath for as long as possible.

(Note: It will never reach 100% saturation because oxygen and CO2 are constantly being exchanged in the body) So if our oxygen saturation levels stay relatively constant, why do we still feel tired, sigh, gasp, and mouth breathe? When we over breathe, we exhale too much CO2 from our bodies. Over time, our body develops a lower tolerance to CO2, telling our brain to breathe more and to breathe faster. Our body becomes programmed to think that it lacks oxygen, even though oxygen saturation levels stay the same. Therefore, the key to get as much oxygen into our bodies is by having a greater tolerance to CO2.

CO2 is a very necessary gas that our body produces during normal daily activities. It helps with:

  • Releasing oxygen from our blood into our tissues and organs.
  • Dilating smooth muscles of our airways and blood vessels.
  • And regulation of blood pH.

Haemoglobin (a protein in our blood) releases oxygen to our tissues when CO2 is present. However, if CO2 levels are lower in our cells, which is often the case with over-breathing, then haemoglobin holds onto oxygen resulting in less oxygen being offloaded or delivered to our tissues. The higher the levels of CO2 in our blood, the more oxygen is released into the cells in our bodies. This is described as the Bohr Effect. In addition to not releasing oxygen, over-breathing also reduces blood flow to our tissues and organs, such as the brain, by constricting our blood vessels. In fact, by decreasing CO2, the diameter of our blood vessels can be reduced as much as 50%! If you add those two factors together — decreased blood flow and oxygen exchange — that is a lot of oxygen our cells aren’t getting.

We know that over-breathing decreases the ability of oxygen being released from our blood to our tissues AND decreases blood flow. Perhaps if we just breathe less, we will feel better? That’s partly true. But the way we breathe also has a global effect on our body systems as well. Part II will help describe how our body changes based on the way we breathe — nasal vs mouth, changes in rate, etc. Part II will also go into some breathing exercises that can help improve our breathing and our BOLT score.

Breathing Self Assessment

Here is a quick assessment to help determine how well you are breathing during rest and exercise. It is called the BOLT (Body Oxygen Level Test) — as seen in ‘The Oxygen Advantage – by Patrick McKeown. It is a measure of how sensitive your body is to C02 and if you are over breathing. The lower your BOLT score — the more sensitive you are to CO2 and the greater likelihood you are over breathing, thus the greater likelihood of breathlessness and early fatigue at both rest and exercise. How to measure your BOLT score:

1. Take a normal breath in through your nose and allow a normal breath out through your nose.
2. Hold your nose with your fingers to prevent air from entering your lungs.
3. Time the number of seconds until you feel the first definite desire to breathe, or the first urge to breathe. These sensations may include the need to swallow or a constriction of the airways. You may also feel the first involuntary contractions of your breathing muscles in your abdomen or throat as the body gives the message to resume breathing. (Note that BOLT is not a measurement of how long you can hold your breath but simply the time it takes for your body to react to a lack of air.)
4. Release your nose, stop the timer, and breathe in through your nose. Your inhalation at the end of the breath hold should be calm. If it is erratic or heavy after 1 or 2 breaths, then you have held your breath for too long.
5. Resume normal breathing.
In an ideal world your BOLT score should be 40 secs, however achieving a BOLT score of >20 secs is a good starter (Note: majority of individuals are ~20 secs). The good thing is that your BOLT score can be improved with breathing exercises (i.e., Buteyko Breathing) with notable changes with every 5 sec increases to your BOLT score.

Reference: McKeown, P. (2022, May 20). How (and why) to measure your bolt. Oxygen Advantage. Retrieved August 4, 2022, from


If you are interested in learning more, our Chiropractor Dr. Ray has a special interest in Breathwork alongside Strength and Conditioning, to book your session with Dr. Ray click here.