In the 1970s, Harvard Medical School cardiologist Dr. Herbert Benson realized deep breathing was a way to alleviate a handful of medical problems, including stress and high blood pressure. To combat these issues, he developed the relaxation response to counteract the "fight or flight" response that comes with stress. At its core, the relaxation response is learning how to breathe deeply as a means of calming ourselves down by stimulating the parasympathetic reaction, also known as the "rest and digest" response, per Harvard Health Publishing.
"The brake works more healthfully than the accelerator here," professor of psychiatry, behavioral sciences, and director of the Center on Stress and Health at Stanford University School of Medicine Dr. David Spiegel told CNN. Deep breathing quickly slows down the heart to a place where stress levels are healthy, explains Spiegel. "We believe breathing is a pathway into mind-body control. It's part of the autonomic system like digestion and your heartbeat, but unlike those body functions, you can easily regulate breathing," said Spiegel. It only takes a few deep breaths for relaxation to start to settle into your mind and body.