DEAR DOCTOR K: How does deep breathing help to control stress?
DEAR READER: When we’re under stress, our muscles tighten, our heart beats faster, our blood pressure rises and our breathing quickens. The relaxation response is the opposite of the stress response; it puts the brakes on the biological changes that put us into overdrive. And it turns out we can elicit the relaxation response at will – by taking deep breaths.
The act of breathing engages the diaphragm and the muscles that hold the ribs together. Instructions from your brain to these muscles cause you to breathe in and out. Most of the time, of course, you’re not thinking about breathing: It just happens. But it is your brain that is controlling it.
And you can consciously control it, as well. Try this:
First, exhale. Then stop breathing for 10 seconds, and then take in a deep breath. You felt your lungs get smaller, and then get bigger, right? How did your brain do that?
When you exhaled, two things happened. The first involved your diaphragm, the strong sheet of muscle that divides the chest from the abdomen. As you breathe out, the diaphragm relaxes. This causes it to rise upward, pressing on the bottom of the lungs and forcing air out of them.
Then, when you took a deep breath in, the diaphragm contracted. That caused it to drop downward, pulling the bottom of your lungs down with it. Since the top of the lungs stayed put, the result was that the lungs expanded, filling with air.
Shallow breathing hobbles the diaphragm’s range of motion. The lowest portion of your lungs don’t get their full share of oxygenated air. That can make you feel short of breath and anxious.
Deep abdominal breathing, in contrast, encourages a full exchange of incoming oxygen for outgoing carbon dioxide. This type of breathing slows the heartbeat and can lower or stabilize blood pressure.
You may be skeptical that deep breathing can counteract stress, but it does. Or, to be more precise, it counters the increased heart rate and blood pressure that stress causes.