Of all the skills I've developed, learning to breathe deeply has given me the greatest return relative to the time and effort invested. One advantage of deep diaphragmatic breathing is obvious- you simply take in more replenishing oxygen. Another benefit, often overlooked, is that breathing deeply, when practiced regularly, is effective in reducing anxiety, muscle tension, fatigue and stress. When a fighter feels tense or overexcited he will often react by either holding his breath or taking rapid, shallow breaths from the upper chest. Both of these responses tend to create even more tension and lead to impaired performance. Studies have demonstrated time and again that a person cannot occupy opposing physiological and emotional states. That is, an anxious mind cannot exist in a relaxed body; nor, can a quiet mind exist in a tense body.

Lie down on the floor and put a book on your abdomen. It should rise and fall as you breathe. If it doesn't, you're not breathing fully enough to produce the relaxation response. Now, replace the book with one hand on your abdomen and the other on your chest. Breathe in through the nose, out through the mouth. Notice how they rise when you breathe in and fall when you breathe out. Most people in Western culture tend to be shallow "chest-breathers". That is, when they inhale only the chest rises and falls.

During inhalation, the diaphragm should move down, pushing the abdomen out and creating space in the lungs. The lungs fill with air from the bottom up. Practice breathing with this focus: push the diaphragm out, forcing the abdomen out. Fill your lungs with air starting at the bottom, and slowly expanding through the middle portion of the lungs by expanding your chest cavity, raising the rib cage and chest. Finally, continue filling the upper portion of the lungs by raising the chest and shoulders. During the exhalation, pull the abdomen in and lower the chest and shoulders to empty the lungs in a "sigh". Let go of all muscular action at the end of the exhalation to promote relaxation in the chest and abdomen.

When I was first exposed to diaphragmatic breathing I consciously adopted a practice of mindfully taking five deep breaths every time I saw a clock or watch throughout the day. This seemed a good way to practice, first, because seeing a clock or watch was a fairly common and regular occurrence, so I was able to get a lot of practice repetitions each day. And secondly, often when I looked to see the time it was because I was in a hurry or running late for an appointment. This gave me the opportunity to practice breathing in mildly stressful situations.

While the exercises can be learned in a few minutes with immediate benefits, persistent practice will produce maximum results. Deep breathing can also be used in conjunction with other strategies such as the meditation or visualization exercises noted in Law #10.