Kan and Lii Kan and Lii have been an important part of qigong training for many generations. Kan represents water and Lii represents fire. Therefore kan is yin, lii is yang. It is believed by qigong practitioners that everyone has excess yang energy and this is why there are so many yin oriented qigong exercises. The exception is if someone is sick then they may have excess yin. Excess yang is thought to play a large role in the aging process. If you can prevent excess yang you can slow down the aging process living stronger and healthier life.