Humans (and mammals in general) are meant to breathe through the nose.

“It was only when our ancient ancestors were in dangerous situations that they reverted to mouth breathing to take in greater volumes of air in preparation for intense physical activity” – Patrick McKeown (writer of The Oxygen Advantage)

Here are some reasons why you should be nasal breathing almost all the time (with the exception of intense physical activity):

• Nasal breathing promotes abdominal diaphragmatic breathing, whereas mouth breathing promotes more upper chest breathing (try it)
• Nasal breathing helps to ensure regular, calm, steady breathing using the diaphragm, where mouth/upper chest breathing is more likely to be associated with a stress response in the body (fight or flight)
• Nasal breathing warms and humidifies the incoming air, and removes a significant amount of germs and bacteria from the air you breathe in – your nasal cavity acts as a filter system
• Nasal breathing creates approximately 50% more resistance to the airstream than mouth breathing, resulting in significantly more oxygen uptake
• Nasal breathing during exercise allows for a much greater training response and promotes an increased VO2 max

Watch a baby breathe, and you will see only nasal/diaphragmatic breathing patterns, as they have not learned bad breathing habits. In addition, animals in the wild will only breathe through their mouths when sick, dying, or in danger

Breathe through the nose for better health and like we were designed to!