SACHA PFEIFFER, HOST:
Good morning. I'm Sacha Pfeiffer. When we sigh, that can signal sadness or frustration. But in the journal Cell Reports Medicine, scientists say sighing, which involves exhaling deeply, can reduce stress even more than inhaling deeply. That's because all deep breathing activates part of the nervous system in charge of how the body rests. Heart rate slows, blood pressure drops, and the mind begins to relax. (Sighs) It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.