This mistake came from the historical and cultural misconception. In China, when we read the old document, the word Qi is different from the word Qi now, there are totally different characters. However, when people began to choose the common character of Qi, which is the wrong one, the meaning of Qi get limited into the air, instead of the old meaning which is energy or vital energy. Later, when people translate these Chinese documents to English or other foreign language, since translators only saw the character which is the common word Qi, naturally they translated it to air or breathing. It is a mistake, a very major misunderstanding of the basic fundamental concept of word Qi. In the west, normally when people think of air, they will think of oxygen and other components in the air, which has no relation with word Qi in Qi Gong at all. So that, please do not figure the word Qi from the aspect of air, they are totally different things in Qi Gong practice.