A World-Weary Sigh
It's a sure sign of frustration, disappointment, resignation and boredom. But sighing has an inspiring purpose, found researchers at the University of Leuven: It resets us, physically and mentally. Breathing too long in a steady, rhythmic state—as we do when worn out—causes lungs to stiffen. That soft, long exhale loosens the air sacs, which leads to a tiny but significant feeling of release.