긴 날숨이 마음을 가라앉히는 이유

Making the exhale longer than the inhale tends to feel calming because the heart slows during exhalation, and a longer exhale increases activity in the parasympathetic "rest" branch of the nervous system. This is why extended-exhale breathing is one of the most reliable calming techniques.

BreathMate Editorial

It is the single most useful thing to know about calming breaths: favor the out-breath.

The mechanism

Heart rate naturally dips during the exhale as vagal (parasympathetic) activity briefly rises. Spending more of each breath in the exhale phase means more time in that calmer state, which is associated with a slower heart rate and a settled feeling. ^[1]

What is well supported

Evidence: Moderate support

Slow breathing with a longer exhale is associated with greater parasympathetic activity and higher heart-rate variability across slow-breathing research.^[2]^[3]

What remains uncertain

The ideal exhale-to-inhale ratio for a given person.
How much of the calming feeling is physiological versus the attention and pause involved.

Practical implications

A ratio around 1 to 1.5 (for example 4 in, 6 out) is a good, comfortable target. Let the exhale be relaxed rather than forced.

Common misconceptions

"The longer the exhale, the better." Very long, forced exhales can feel strained and are not more calming.
"You must empty your lungs completely." A soft, comfortable exhale is enough.