Correct breathing (Ho Hub) is essential during martial arts practice for the obvious benefit of drawing in fresh air to power the body.  Correct breathing technique employs the Dan Jon, which is the lower portion of the abdomen just a few inches below the navel, and represents the central generation point of concentrated inner power known as Ki.  Below is a photo of Grandmaster Kim Soo at HQ in Houston leading a black belt class through the Breathing Form, which is Dan Jon Ho Hub, or Ki building exercise hyung. Richard Griffin can be seen in the background (white uniform) following the step-by-step instruction of Grandmaster Kim Soo.  This form is unique to Chayon-ryu and is one of many such forms preserved and passed through generations by our system.