The dance of breath.

Breathing is a dance with the atmosphere. We repeat a delicate exchange of gases some 20,000 times a day, nurturing every cell in our body. We take in oxygen and expel carbon dioxide with each breath. It sounds simple, but the actual physiology of breathing is quite complex.

Every part of the body needs oxygen, but it is carbon dioxide that regulates the release of oxygen to the cell. Oxygen can only be released in the presence of carbon dioxide, which maintains the chemical balance. You can think about carbon dioxide as the delivery mechanism for oxygen to get into your bloodstream.

While the body normally breathes without help from the conscious mind, we can choose to control the way we inhale and exhale. Although we are always being told to "breathe deeply" in order to relax, most people over breathe. This means they take in too much oxygen, leaving too little carbon dioxide in the A bloodstream. This happens especially when we breathe through our mouths.

For dancers, breathing through the mouth is less efficient. Robert Litman, creator of The Breathable Body workshops in Tucson, Arizona, says, "Mouth breathing creates a carbon dioxide deficit which actually prevents oxygen from getting to the cell. The bottom line: You will feel sore and tired due to a lactic acid build up." According to Litman there are three main components to optimal breathing that can help dancers improve overall health.

Breathing in and out through the nose: The respiratory system begins with the nose. When we breathe through the nose, we filter the air, blocking out harmful pollutants and allergens. We also moisturize the air and heat it to body temperature before it enters the lungs. Nose breathing activates all five lobes of the lungs (mouth breathing only activates the top two lobes). We also avoid taking in too much oxygen, thus preventing over breathing or hyperventilating.

Belly breathing, or using the diaphragm: The diaphragm is located right under the ribs and divides the chest from the abdomen. With chest breathing, the air enters only the top of the lungs. Breathing low into the belly inflates more of the lungs, improves oxygenation of the entire body, and creates the vacuum that naturally pulls air into the lungs.

Keeping the mouth closed: Even during heavy exertion, you need to keep your mouth closed in order to recirculate the carbon dioxide. This will take some training if you are used to gulping for air. Next time you go out for a run or fast walk, try keeping your mouth closed for long stretches. If you feel the need to gasp for breath, simply slow down until you can resume breathing through your nose. When you have to open your mouth you have outpaced your body.

There are also aesthetic concerns. For instance, panting can draw attention to the dancer that may not be part of the choreographer's intention. Tobin Del Cuore, of Hubbard Street Dance Chicago, is used to dancing at break-neck speeds. "Sometimes I don't want my exhaustion to show," says Del Cuore. "I always think of myself as a character even in the most abstract pieces, and the mouth is a part of that. Sometimes it's sheer force of will to get through a difficult dance." Before a show Del Cuore tunes into his breathing as a mental Preparation.

Sara Rudner, director of dance at rah Lawrence College and a veteran of many rigorous dances with Twyla Thaw, says, "Dancers can be unaware of the anatomy of their breathing--what happens with the diaphragm and the muscles around the rib cage, and how that affects the engagement of the whole self." Rudner finds that reviewing breathing basics is a good way to begin the training process.

According to Robert Litman, with some retraining it's entirely possible to dance at high speeds with a closed mouth. Remember, yoga and the martial arts have advocated nose breathing for some 5,000 years. Consider actress and martial artist Zhang Ziyi's powerful closed-mouth performances in Crouching Tiger, Hidden Dragon and House of Flying Daggers. Should you find yourself in a dance that is about exhaustion, an open mouth may be necessary to get that idea across. But when it s over, close your mouth, gather up that precious carbon dioxide, and return to your pas de deux with the environment. See www.thebreathablebody.com or www.breathdance.org.

Nancy Wozny is an arts and somatics writer based in Houston.