Horizontal breathing causes the chi to stick in the upper part of the body. Horizontal breathing is the shallow breathing that is marked by the in and out movement of the lungs at the upper chest level. Vertical breathing allows the chi to flow to the lower parts of the body. Vertical breathing flows deeply into the abdomen and can be seen with the rising and falling of the diaphragm as well as the movement in and out at the waist level as the air fills the lower part of the torso.
When muscles are held tightly the breath stays up and cannot sink. Softness leads to good circulation and health and to a good connection with the dantian and internal energy.