Reverse breathing gets its name because it is, in many ways, the reverse of natural breathing. To try reverse breathing, inhale deeply, contract your abdomen and fill the upper part of your lungs. When you exhale, push your abdomen out, and drop your breath within the body. Because of the decrease of pressure in the lungs (increase of volume) the diaphragm will move down, so consequently, the organs in the abdomen will be contracted. Everyone has used this type of breathing, whether you are conscious of it or not. It is the way we instinctively breathe when pushing something heavy. The breath moves vertically, up and down within the body, like a pump. Click to learn how Chinese medicine treats Adenomyosis.
Interestingly, during reverse breathing, the breath also moves horizontally, moving backwards and forwards inside the belly during exhalation. (A common Daoist technique is to imagine a pearl moving back and forth). I find reverse breathing a useful technique to use before meditation practice. It is important that you never let this become your natural way to breathe. Over-practice and incorrect practice of reverse breathing can lead to medical problems. I would not recommend anyone with high-blood pressure to practice reverse breathing. While I am not a medical professional, I was taught that exerting too much downward pressure on the lower abdomen can cause hemorrhoids, and too much upward pressure on the stomach can contribute to acid reflux problems. Techniques like moderating the amount of force used, and lifting up the pelvic floor can be used to prevent straining the breathing muscles, so is important that any advanced breathing techniques be learned and practiced under the supervision of an experienced teacher.