"Qigong and Tai Chi both make use of the Qi energy that runs through the body. That qi energy is moved about through the acupuncture energy channels of the body, by use of the mind. “The mind intent leads the qi energy, and the blood follows” is an old training adage. It is the blood that is following the qi, that brings about the greatest health benefits. If using imagination, little to no blood flow, because the mind is not really moving the qi. In imagination, the mind pretends to move the qi. In using mind intent, catching the feeling of the qi is of primary importance. Once the feeling of the qi is found, the mind intent ( Yi Nian - 意念) can easily move and guide the qi."
Catching the feeling of the qi can be easy or complicated, depending on your qi sensitivity. If you are a qi sensitive, it can be felt right away. If you are a qi insensitive it may take years of looking to catch the feeling of the qi. Most people are somewhere in between. The feelings of the qi are: hot, cold, jump about, fullness, pressure, distension, itch, pain or electrical feelings. Sometimes it is also felt as a menthol feeling, this usually falls under the cool sensation, but I can notice a difference between menthol and cold. Once you have caught the feeling of the qi, which is recognition of its sensations, the qi energy can be easily led along the qi pathways throughout the body.
"To the Internalists, the body is an empty vessel, an external shell or form (Xíng形in Mandarin Chinese). To have a functional meaning, the empty vessel must contain something called "Yi" (Intention 意). Yi is not some kind of cosmic energy floating in the universe around us, and gathered with fancy movements. It is a physical manifestation of the thought of doing an action."
"The highest level of training one's Yi in the Internally-oriented arts, has been referred to in the Xing Yi Quan classics as: 'A fist without a fist, intention without intention – within the absence of Intention, lays the true Intention'."