This is fascinating stuff:
"How Breathing Through Your Nose Will Change Your Life with Patrick McKeown"
I know that some of us have been concerned that our breathing can be too fast or shallow. Well, here Patrick McKeown explains how this may well be true and that mouth breathing often equates to chronic over-breathing. He describes how breathing through the nose rather than the mouth can:
relax us - mouth breathing stimulates the fight or flight/sympathetic nervous system because we take fast, shallow breaths when under threat; while we breathe gently thru the nose when relaxed. So by nasal breathing as much as possible we give the brain the message that we are calm.
alleviate sleep apnea by not breathing through the mouth at night.
allow us to take slower more satisfying breaths as it far more natural to breathe using the diaphragm with nasal breathing.
enable a healthier cardiovascular system as nitric oxide (which enables blood vessel dilation) is produced in the sinuses and therefore much more readily available via nose breathing.
I've certainly noticed I'm dropping off to sleep far more quickly after trying this for a few days.