You see, most people, when instructed to do a deep breath, will actually do a "big breath." They breathe in sharply (and loudly), the chest rises and all sorts of effort goes into doing this so-called relaxing deep breath. Neck and shoulder muscles that are already tense and tired, work a bit more to lift the chest. Too much air goes through the lungs. Too much air? Can you breathe too much? Yes! And when you do, it disrupts the body's natural breathing rhythm and deregulates respiratory chemistry (meaning the balance of oxygen AND carbon dioxide). Ultimately, there is less oxygen available, not more. Try it yourself right now. Sitting there, spend a minute taking deep breaths as I described above. Breathe in purposefully through the nose and fill your lungs up all the way and breathe out, maybe even through the mouth....
Now how do you feel? Lightheaded? Foggy? Tingling in the lips? If so, that's an indication that you were breathing too much. If you feel better, two things might be the case. One, you have mastered deep breathing (yay!). Or two (which is more likely), your perception of your own breathing is influenced by what you think deep breathing should do for you. That is, you've been told that deep breathing is good for you, so therefore when you do "deep breathing" you assume you feel better after, no matter what the sensation is.
For many people, there is a lot of difficulty separating a deep breath from a big breath. When I say deep breath, I mean a nice slow, effortless inhale using the diaphragm muscle; the belly expands and the chest stays still. But for those that have adopted an upper chest breathing pattern - maybe through posture issues (are you hunched in front of the computer as you read this?) or because of poor stress management, trying to do that belly breath is nearly impossible. And so when they practice deep breathing exercises that they've been taught from various sources (friends, yoga instructors, internet sites, etc), they move right through into big breathing, which ironically, stimulates the flight or fight response, not settles it!
The key to deep breathing is to re-establish the natural deep pattern of breathing, but also match that with your own body's unique breathing rhythms and respiratory chemistry requirements. When we can match that up, we get optimal respiratory fitness. And what you might find, is that instead of needing to take a deep breath every time the tension ratchets up a notch, you can actually manage to keep things on track by maintaining a natural breathing pattern to keep stress at bay.
To find that optimal zone with my patients, I use observations of breathing patterns, monitoring of muscle tension and respiratory chemistry analysis using a CapnoTrainer to be as accurate as possible. Because while there are lots of ideas out there about breathing, it is important to note that breathing is a science, not an art!
Next time you are feeling rushed or stressed and you go to take a deep breath - check in with yourself to see if it truly makes you feel better. If you can hear your breathing or feel your chest rising sharply, chances are it's not helping. Which means it might be a good idea to restore your natural breathing pattern so you actually get the benefits of "deep breathing" that you are looking for.