As yoga and pranayama (generally breathwork) has become more popular and wide-spread in our culture, my interest in the science behind the claimed benefits has also peaked. Not only am I really curious about understanding the physical chemistry going on during such practices, but I practice myself, and have a passion for understanding and sharing evidence based methods for improving personal, social and environmental health and well being.
One of the core understandings in breathwork science, especially related to “intermittent hypoxia breathwork” is called The Bohr Effect, named after the Danish physiologist Christian Bohr who described it in 1904.
The Bohr Effect describes the ability of red blood cells to adapt to changes in the bio-chemical environment. It specifically describes hemoglobin’s lowered affinity for oxygen related to increases in the presence of carbon dioxide which causes lowered blood pH. This lowered affinity allows oxygen to detach from hemoglobin and move into body tissues thereby meeting the oxygen demand of the tissue.

The Bohr Effect Simplified
Here is a simple point form description to help understand the Bohr effect.
- The work of the cells in the body (cellular respiration) releases CO2 as a ‘waste product’
- This waste product causes lowered pH (a more acidic environment)
- Lower blood pH decreases the strength of hemoglobin’s affinity for O2 leading to the release of O2 from the hemoglobin for it’s transport into the cells. Cellular waste product attaches to the now binding sites on hemoglobin and get carried back to the lungs via the bloodstream
- Back in the lungs there is a relatively greater O2 saturation and the blood pH is higher (a more alkaline environment. Hemoglobin’s affinity for O2 increases and oxygen again binds to it getting transported to the cells of the body
- The cycle continues!
Naturally, there is a lot more scientific detail that could be articulated in the process, but if you understand cellular respiration and the Bohr Effect even just as described above you’re well on your way to a stronger understanding of the breathwork science behind the practices I teach such as “brief intermittent hypoxia.”
For a thorough read of the chemistry going on in the body check out this article describing the Bohr Effect in depth. To go even deeper into specifics you can research the Bohr Effect vs the Haldane Effect (the effect of CO2 on O2 transport vs the effect of O2 on CO2 transport).