Xing Yi Chuan
(Shape Intention Fist & Qigong)
Xing Yi Chuan and Sichuan Xin Yi Chuan, are 2 powerful internal martial arts. Xing Yi is often translated as Shape Intention Fist, and Xin Yi as Heart Intention Fist. Xin Yi Chuan was said to have been developed by General Yue Fei, an eagle claw and spear master who integrated many concepts from both of these arts. Later on Xing Yi developed from Xin Yi.
Both Xing Yi and Xin Yi have became known as an extremely powerful arts. Because a martial artist and warrior needed to be healthy to fight, many health building aspects were integrated into these arts and so health and longevity became almost a side-effect of practicing Xing Yi and Xin yi. One can not help but get stronger practicing these arts.
Many Taijiquan practitioners supplement their art with Xing Yi / Xin yi because the yang energy of these arts balances the Yin movements of modern Taijiquan.
Xin Yi contains movements based on 6 animals (10 in other traditions). Xing Yi, crated within the last few hundred years, contains the 5 element fists, and 12 animals. The 5 elements are based on directional flows of energy as well as organ energies, and help generate energy when practiced using the creative cycle of these elements (Wood creates Fire creates Earth creates Metal creates Water and then back to Wood). When using the destructive cycle, a martial artist would be able to neutralize and destroy any attack. The 12 animals have many martial aspects as well as health aspects.
Xing Yi and Xin Yi both develop will power, internal strength, confidence, and Yang energy needed for health. I consider this art the foundation of all internal fighting arts and a necessary component for health if you are a Taijiquan practitioner.
General Yue Fei from Wikipedia