The martial arts and yoga are both schools that teach physical stretching exercises, and they both emphasize internal energy cultivation, or neijia. The martial arts also emphasize ideal body alignments and physical movements so that you can express tremendous muscle power together with Qi energy for physical attacks or defense. To reach the highest levels of yoga and martial arts you need to learn how to lead your Qi efficiently, and match its power with your physical movements. You need to be pursuing a mental and physical state of flow by cultivating internal Qi movements.
There are many techniques that work on cultivating the Qi (Prana) of muscles, organs and bones; meridians or Qi circulatory orbits; muscle force transmission pathways; bindus, marmaor acupuncture points; appendages such as arms and legs; body cavities such as the three dantian, chakra sections and other sectioning schemes; and simple body parts (such as the ears, eyes, teeth, penis, and so forth). In yoga and the martial arts, you normally learn how to cultivate the Qi within all these separate sections via body alignments, specific physical motions and energy exercises until you can sense and control your body as a single energy unit. You can stimulate and cultivate your Qi via special breathing exercises, visualizations, sound vibrations, emotional states, and through your will or special absorptions. Especially within the martial arts, you need to know how to cultivate these various techniques to purify your Yin and Yang Qi to progress to higher achievement levels.
Most all of the different ways of purifying your Qi focus on small segments of the body instead of just a single whole body that you attempt to cultivate all at once. As the segments become more purified, this helps to open up the Qi channels within those regions, their Qi flow becomes free of impediments and also becomes smoother. As a result, martial power can be expressed quicker and more fully. All the segments of your body, regardless of how you partition it in nei-gong exercises, and regardless of what techniques you use, must be "washed" with Qi or Prana. At the same time, it is useful to hold onto specific emotions to purify their Yin and Yang composition.
Here is a guidebook for how to pursue these types of cultivation, and the unified mind-body state of flow where there is a sense of control over any agency while your mind remains focused, quiet, and alive in experiencing the moment. This is the sat, chit, ananda target of Yoga, the "no mind and no body" target of Zen, and the blissful state of "no extremities" within the martial arts. You reach it when you can finally control the entire underlying energy matrix of your physical body, which is the ultimate purpose of yoga and the martial arts such as in the schools of Emei, Wudang and Shaolin.