It is a common misconception that breathing comes from the upper chest. Yes, the muscles in the neck and top of the chest are accessory breathing muscles, but not the primary ones. Breathing should come from the belly. The primary breathing muscle is actually the diaphragm. Proper breathing is therefore known as “diaphragmatic breathing” or “belly breathing”.
Why, you ask, does this matter? Breathing improperly puts unnecessary stress on the body. You can not fully oxygenate each cell if the breath you take does not originate with the diaphragm and does not completely fill the lungs. Avoiding a slouched position also helps optimize the amount of air that can be pulled in.
As illustrated below, proper breathing should initiate with the diaphragm contracting and lowering, and secondarily the chest expanding. Air should be pulled in primarily through the nose as the tiny hairs that line the nasal passage are the first line of defense against dirty particles in the air. Exhalation should follow the reverse pattern, with the carbon dioxide that is released coming out largely through the mouth.
If you want to read more on this, please visit: https://www.britannica.com/science/human-respiratory-system/The-mechanics-of-breathing
And if you would like to practice an exceptionally calming breath, let your inhalation occur over the duration of four counts, pause for moment with you breath inhaled, then double your exhalation, letting it release over eight counts. Reconnecting with your breath in this way has many benefits, including but not limited to calming the nervous system, lowering blood pressure and clearing the mind. Happy Breathing!