Take a moment and notice breathing. What is moving with each inhalation and exhalation? The shoulders? The chest? The belly? Is air coming in through the mouth or in through the nose? What about on the exhale, through the mouth or through the nose? Does it matter? Why?!
Simply put, mouth breathing stimulates the fight-or-flight response in the human body. It excites the sympathetic nervous system. This is great if the body needs a rush of energy and hormones to flee from a dangerous situation. It is damaging to human health, however, if the body is in a constant state of fight-or-flight. The stress it causes breaks the body down and has significant long term effects on both healthspan and longevity.
Inhaling and exhaling through the nose puts the body into the parasympathetic nervous system - the rest-and-digest state. This is where most humans need their body to be most of the time. It is a calm and relaxed state of mind and body.
Nose breathing is also highly effective during sports and physical activity. By breathing through the nose, an athlete or weekend warrior can maintain a lower heart rate, as well as lower it more quickly after intense bursts of movement. Breathing heavily through the nose will feel forced at first, but with practice, it will become second nature and ultimately lead to improved physical performance.
The next factor to focus on in healthy breathing is expanding and contracting the belly by using the muscles of the diaphragm. Many people inhale by raising the shoulders or expanding the chest. They then exhale by lowering the shoulders or collapsing the chest. This is a mistake. Watch a dog or cat breathe - either at rest or when being active - their bellies expand and contract. This is where a breath should occur in humans as well.
Take a moment to practice this motion. Start by gently placing the hand against the bellybutton. Take a deep inhalation and press the belly into the hand. Next, exhale and feel the hand move in towards the spine. Repeat for 5-10 slow and controlled breaths.
How one breathes matters. Make an effort to be more aware of breathing techniques both at rest and at play. Focus on inhaling and exhaling through the nose, as well as expanding and contracting the belly with each inhalation and exhalation. The mind and body will be healthier for it!