Deep breathing, also known as belly breathing  or diaphragm breathing, is widely used in meditation and mindful movement practice today. It is known for eliciting a soothing effect, lowering heart rate and blood pressure, and increasing emotional regulation. Simply put, it makes you feel relaxed and calm.

Historically, deep breathing has been used across cultures. We know it has been used in various meditation practices in the East, but it was also practiced in the West as early as the Roman era.

Galen, the physician for the gladiators of the Roman Empire over 1,800 years ago, stated that breathing utilizing the abdominal muscles and diaphragm is important for health in humans. His view on ‘abdominal diaphragm breathing’ was elaborated in detail by Leonardo da Vinci, the 15th century Renaissance artist.

da Vinci observed that all things in the universe are connected to each other and breathing in essence is a non-isolated bodily process which is aided by the gastrointestinal tract and the abdominal muscles. He emphasized that the stomach muscles must relax during inhalation, because when the stomach muscles relax, the bowels descend, pulling down the diaphragm. When the diaphragm descends, the lungs open, taking in air. During exhalation, the condensed air in the compressed intestines, together with the contraction of the abdominal muscles, thrusts the diaphragm upwards. Then the diaphragm compresses the lungs, expelling the air out of the body.

Statue of Leonardo da Vinci in Amboise, France.

Galen’s and da Vinci’s abdominal diaphragm breathing is consistent with the belly breathing we practice in modern day meditation. Despite possible differences in their interpretations and applications, both belly and diaphragm breathing seem to have a similar effect in the body and mind.

Physically, the movements of the belly and diaphragm are not separate but collaborative continuous entities linking the gut and chest regions. They are connected systems that augment and complement each other for optimal bodily function by increasing and decreasing the amount of oxygen in the body.

In addition, when you breathe deeply, the belly expands and the diaphragm contracts (moves downward) beyond the normal range, stretching and massaging the organs and intestines. These organs are rich with connection to the “vagus nerve”, the longest parasympathetic nerve linking the guts, the lungs, the heart, and the brain. Not surprisingly, recent studies have shown that there may be the second brain in the gut area facilitating the gut-brain-gut communication. 

Activation of the vagus nerve relaxes the body. That’s why you feel much calmer after taking a few deep breaths. In this mode, our body consumes less energy; the mind labors less; the heart rate and blood pressure drop. The gut, heart, and brain become in sync working as one.