system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does taking a deep breath calm you down?
gpt
A simple answer is that deep breathing increases the amount of oxygen in your body and slows your heart rate, helping you feel more relaxed. Another reason is that it activates the parasympathetic part of the autonomic nervous system (ANS), which is responsible for controlling our rest and relaxation.

The other half of the ANS is called the sympathetic nervous system and deals with the fight-or-flight response, and is associated with fast, short breaths.


Also by focussing on taking deep breaths, you take your mind off of whatever is making you stressed.