The importance of being having whole body power in Internal Martial Arts cannot be understated. To have Fa Li (power) one must have Guo 裹. Most IMA individuals understand Guo in terms of wrapping Jin. It’s a horizontal energy (oversimplified term, all directions are present to ensure centeredness) used for defense and offense. It takes an opponents incoming energy and wraps around it, cutting it off or better yet absorbing it to re-issue.
Great Sifu you defined Guo, so what? Why is it important?
Guo can be fundamental to absorbing and issuing. All fighting arts look to “suck” in their opponent and take advantage of the position. Blocking is easy but true masters in their chosen art can off-balance their opponent, using their opponent’s strikes and aggressiveness to their advantage. It is circular, coiling, redirecting. You must connect with your opponent, overturn and coil around it, lead it into emptiness. It allows you to gain the upper hand or superior position for the attack. It allows you to gather energy in your joints to release quick and sharply like an arrow.
Some masters will talk of Guo at a deeper level. They will associate Guo with connection and togetherness. The wrapping methods of Guo require the practitioner to connect the Sānjié (三節) or three sections through coordinated movement. The wrapping methods need to be coordinated in the legs to root and absorb, the waist to maintain centeredness and twist as the arms to overturn and accept, and the head to be upright to allow for the energy to sink and gather. When all of this is coordinated it will maximize the effectiveness of your Jin. Now as you get older this Jin will be harder to accomplish as joints and aches will get in the way of coordination. This is one reason to remain soft and supple; to ensure things can connect smoothly and work in harmony. If you do not practice consistently and work towards song/suppleness you will become “scattered.” This will show in your wushu and is something you want to delay in old age as long as possible. Discipline, consistency, hard work — the mantra of the wise, the mantra of wushu experts who can obtain and maintain Guo well into their old age!