eli5: why do most, if not all, breathing techniques specify ‘out through the mouth’?

Question

i can understand in ‘through the nose’, since dust and other bits can be blocked by the nose hairs and mucus, and apparently the air is more likely to warm up when passing through the nose first, reducing irritation of the throat.

but what difference, if any, does exhaling through the mouth make?

In: 676

Answer 1

You cant control the outflow from your nose.
You can change the size of your mouth to adjust the outflow.

For breathing exercises, controlling the volume of the outflow is important, and its a little easier to fully evacuate your lungs when you can control the speed.