Upper-chest breathing is more likely to be associated with a stress response, while nasal breathing helps ensure regular, calm, steady breathing using the diaphragm. The common misconception of taking a “deep” breath is to puff out the chest and raise the shoulders, but this is neither deep nor beneficial to oxygenating the body. To help deal with stress, the instruction to take a deep breath is actually correct, but a truly deep breath is abdominal, gentle and quiet; the exact opposite of the big breaths usually taken in an attempt to calm down.
