“Breathe Deeply.”
“Take a deep breath.”
We hear this all the time. Well, from my perspective we generally are being led in the wrong direction.
Note, I’m not a doctor, I simply look at what I see, experience and the physics/biology of this as it appears to me.
The instruction to “breathe deeply” seems valid on paper: Deliver more oxygen to the muscle through a bigger breath.
However, what if it did the opposite? The “deep breath” typically refers to a larger volume of air, taking a “big breath” in and a “big exhale.”
The end result here is a net decrease in CO2 levels in the blood. CO2 is often considered a “waste gas” by many, however CO2 is one of the main drivers for oxygen delivery to muscle tissue (via the Bohr Effect).
We also know this from exercise – as the cellular respiration increases, there in an increase in CO2 levels in the body. A “deep breathing” pattern is used (alongside mouth breathing usually) to expel this excess CO2.
However, any “deep breathing,” or over-breathing during a normal state of being will typically reduce oxygen delivery to the muscle.
CO2 is also a calmative and “vaso-dilator,” which means it helps to relax the body and nervous system and can help increase blood flow throughout the body. A lack of CO2 (via over-breathing) would mean vaso-constriction, which is the opposite of what we are after.
While deep breaths may have some benefit prior to a breath-hold effort (by reducing CO2 levels in the body prior to a breath hold), their benefit in movement activities or everyday life seems counter-productive.
On the contrary, the subtle breath, or slow breath (reduced breath rate) increases CO2 (calmative and vaso-dilator), will increase temperature and metabolism and help oxygen delivery to the muscle.
