First, let us consider natural breathing. When you practice Taijiquan with this breathing, your mind does not have to be focused on the breathing. This is especially important for the beginner. At this stage, they should pay attention primarily to regulating the body into a more relaxed, centered, and balanced state.
Once you have regulated your body, then you should learn how to regulate your breathing so that it is more efficient. Breathing is considered to be your strategy in Chinese Qigong. How you coordinate your breathing allows you to regulate your body and lead your Qi efficiently. There are two common ways of breathing in Taiji. The first way is called "normal abdominal breathing" or "Buddhist breathing", while the other is called "reverse abdominal breathing" or "Daoist breathing." In normal abdominal breathing, when you inhale the abdomen (or Dan Tian) expands, and when you exhale the abdomen withdraws. However, in reverse abdominal breathing the abdomen (or Dan Tian) withdraws when you inhale, and expands when you exhale. It is usually easier to keep your body relaxed and feeling comfortable with normal abdominal breathing, so that is the method commonly used by those who practice Taiji only for health.
As for reverse abdominal breathing, many Taiji practitioners today falsely believe that the reverse breathing technique is against the way of the Dao. That is not true. It is simply used for different purposes. Try this simple experiment. Place one hand on your abdomen, and hold the other in front of you as if you were pushing something. Inhale deeply, and as you exhale, imagine that you are pushing a heavy object. You will easily see that, when you try to push as strongly as possible, you automatically use reverse breathing. This is the method which is commonly used in weight lifting competition. The competitors often wear a thick belt to support their abdomens and increase their power.
The rationale for reverse breathing is quite simple. You can lead a much stronger flow of Qi to the limbs and manifest more power if you also, simultaneously, direct another flow of Qi to your Dan Tian. This is in accordance with the basic law of physics which states that for every action there must be an equal and opposite reaction. If you are still not convinced, try another experiment. Blow up a balloon while holding a hand on your abdomen to see how it moves.
You can see from these experiments that reverse breathing is in accordance with the Dao. It should be used whenever you need to lead Qi to the limbs to efficiently manifest power, as when fighting. Because reverse breathing expands the Qi and energizes the body it is considered Yang, in comparison to normal breathing which is Yin.
You can see from this discussion that both normal abdominal breathing and reverse abdominal breathing are correct, depending on your purpose. It is just like how you breathe during your everyday activities. You should understand that the way you breathe is affected by your thinking and your emotions. For example, when you think of something scary, you will naturally tend to hold your breath. When you are sad, you inhale more than you exhale, and when you are excited, you exhale more than you inhale. When you are relaxed, your breathing is uniform and natural, and when you inhale your abdomen moves out, while when you exhale your abdomen moves in. However, when you intend to manifest power, or even just think about it, you automatically change to reverse breathing.
Theoretically, normal abdominal breathing makes you relax and allows the Qi to circulate smoothly, and reverse abdominal breathing makes you tense and excited, which allows the Qi to be manifested in your physical body. You can see from this that normal abdominal breathing can make your physical body and mind calm, which is considered a Yin practice. Naturally, reverse abdominal breathing can make you excited and energized, and it is considered Yang.
I therefore suggest that, if you are interested more in the health aspect of Taijiquan, you should emphasize normal abdominal breathing. However, if you practice Taijiquan for martial arts, then you must also practice reverse abdominal breathing and learn how to lead Qi to your limbs efficiently.
Dr. Yang has been involved in Chinese Gongfu since 1961 and has more than thirty years of instructional experience. Dr. Yang has published twenty-four books and twenty-eight videotapes on the martial arts and Qigong. Currently he is president of Yang's Oriental Arts Association, Boston, MA.