Introduction
The term "Internal Kung Fu" (Nei Gong, 内功) has acquired two layers of meaning in contemporary discourse. One refers to Qigong (energy work) practices; the other refers to the training content of traditional martial arts. Most people's understanding of "internal power" comes from martial arts novels — concepts like "Great Celestial Cycle" (Da Zhou Tian) and the "Ren and Du Meridians." These elusive concepts originate from Traditional Chinese Medicine theory and later developed into Qigong. Whether Qigong's "internal power" has the miraculous effects described in novels, I will not comment. I will only discuss what I know: what "internal power" means in Chinese martial arts.
External vs. Internal: Understanding the Difference
In Chinese martial arts, there is a saying about "Internal Styles" (Nei Jia), which includes Tai Chi, Xing Yi, and Bagua Zhang. This distinction emerged in the Ming and Qing dynasties and has been debated ever since. So what is "Internal" and what is "External"?
A relatively reliable explanation within martial arts circles is this: Most Chinese martial arts evolved from ancient battlefield long-weapon techniques. Early long weapons were mostly rigid poles, requiring strong limb strength to wield. The boxing forms derived from them are "External." Later, flexible-pole long weapons appeared. Using flexible poles required mobilizing waist-abdomen power, leveraging the pole's resilience and heavy-object momentum to generate greater damage — think of a sledgehammer. A rigid-pole sledgehammer requires tremendous strength; a flexible-pole one is far more effective. The "Internal vs. External" distinction essentially describes this difference.
From this perspective, the questioner may be disappointed. "Internal power" trains such simple things? It seems completely unlike the magical descriptions in martial arts novels. I can only say: simple and direct things are effective things. In ancient times, people practicing martial arts did not do it for fun — basically, they needed to make a living and were willing to engage in real, life-and-death combat. Flashy movements were useless; being able to strike the opponent hard and with sufficient force was what allowed one to survive. Striking first and with greater force — that was the purpose of training. Therefore, the "Internal" of martial arts is not mystical at all.
The Essence of Internal Power: The Dantian
The purpose of internal power is very simple and direct, but acquiring this simple and direct ability is no easy task. Casually throwing a punch that looks light and floating, yet being able to send an opponent flying upon contact — this ability requires long-term, systematic training.
The above describes "what internal power is." Now let us discuss "how to cultivate internal power."
Martial arts novels often mention "Pre-Heavenly Skill" (Xian Tian Gong). In martial arts, this concept exists but is completely different from Qigong's descriptions, and has no relationship with the "Pre-Heavenly" and "Post-Heavenly" Bagua concepts in the I Ching. So what does "Pre-Heavenly Skill" refer to? It refers to the method a person uses, while still in the womb, to stretch, twist, and kick. Fetuses, including newborn babies, have soft bones and small limb strength. All their movements are centered on the waist and abdomen. When lifting a hand, the feet also kick outward. When turning over, they completely do not use limb strength but "wriggle" through body expansion and contraction. All these point to one issue: the original source of human power comes from the waist and abdomen.
As a person gradually grows, bone strength gradually increases, and limb strength gradually grows. Our force-generation methods then change. Lifting a cup requires no foot-grounding, chest expansion, or back straightening. However, when encountering an emergency situation requiring maximum force output, we still use this "maximum output method." But to achieve this output state, conditions must be met. You must first have tried it — knowing how heavy the items you lift, push, pull, and press are — before your preparatory posture basically conforms to the key points in internal martial arts. And this magical "internal power cultivation method" is what allows you to maintain this degree of preparation at any time, and to quickly and effectively deliver your maximum force onto the opponent's body center of gravity, causing them sufficient harm.
Clearly, this "internal power" is no benevolent discipline. Using this kind of fierce, aggressive approach to also "enlighten to the Way and meditate to achieve the fruit" — I personally feel this is quite unreliable. Martial arts are martial arts; dragging in other irrelevant things is inappropriate.
Cultivation Method: From Stance to Moving Forms
If you carefully observe, you can see that the center of all my preceding text is two characters — "waist-abdomen" (Yao Fu, 腰腹). These two characters seem unimpressive. Let me rephrase: "Dantian" (丹田). Is this not far more dignified and commanding? The so-called "Dantian power" of internal martial arts is actually training centered around the waist and abdomen.
If you imagine "qi" as a mass in your Dantian, this "qi" will not leak out and become a foul odor; rather, it "sinks to the bottom" (sea bottom), passes through the "Gate of Life" (Ming Men), goes up to the "Hundred Meetings" (Bai Hui), and down to the "Bubbling Spring" (Yong Quan) — becoming a warm current flowing endlessly through the Ren and Du meridians... then this is no longer within the scope of martial arts. I must say: if it could really flow out, it might be usable as a (unpleasant) self-defense tool. Alright, stop. Let us discuss this waist-abdomen.
So, what next? In the transition from "stilness" (stance) to "movement" (moving forms), after obtaining the sensation through stance training, one must maintain this state during movement. Finally, there is partner practice — testing and refining in simulated combat.
Internal martial arts condense all practices into one character: "Whole" (Zheng, 整) — not the "whole" of "whole person" but the "whole" of integrated wholeness. The preceding text mentioned that a casually thrown punch, seemingly light, can send someone flying upon contact. In reality, this punch has already concentrated all mobilizable power and potential energy, like swinging that flexible-pole sledgehammer. Furthermore, after adjusting the positions of each joint, no precursor movement is needed before attacking — there is no retreating to create distance. Power is generated internally, and the punch is delivered without warning, also appearing as if full force were not being used. But upon contact, that penetrating power causes tremendous damage.
Conclusion
True martial arts cannot be popular among the general public; they have always been "rare melodies for the elite," the plaything of a very small number of people. If you wish to avoid detours on the martial arts path, seek true transmission. Internal power is not a mystical superpower but a scientific method of structural training, breath coordination, and mental focus. Through persistent stance training, moving forms, and partner practice, one can gradually approach the true meaning of "internal power."