I'm trying to figure out what, precisely, Kiai means.

I've done some reading, and am aware that the Kiai is supposed to come from the Hara, or Dantian - the stomach area.

Literally Kiai, means 'join energy', but Ki can refer to the mystical energy force from Chinese medicine as well as just 'energy' in the western context.

Reason this is interesting is that the Dantian is the 'Sea of Ki', presumably a reservoir of it - so is there some deeper meaning to this? Is there some mystical connection, with the kiai bringing forth one's Ki up and out of the body? Or is it just an etymological coincidence?

  • The Dantian is also the physical centre of mass of a human. It moves with your posture.
    – Huw Evans
    Mar 14, 2019 at 16:19

6 Answers 6


Ki (気) does mean "energy" or "mood", but the A (合) is just a shout of enthusiasm (Korean does use the energy+join setup with K'ihap), so no, there's nothing mystical about it any more than a sports team breaking their huddle by shouting something like, "go team!"


You are mixing world religions and confusing Chinese chi with Japanese ki. This is problematic. They are different interpretations of mystical force.

Since you used the term "kiai" I will speak from the Japanese interpretation since kiai is a Japanese word.

The usage and meaning of kiai varies depending on context and origin. The Japanese have many thoughts on kiai and it is represented mostly in martial arts.

In martial arts you either have physical styles that focus and destroying the opponent or you have spiritual styles that focus on metaphysical analysis of phemenoma that can not be explained readily in western scientific terms.

Physical styles vary in their approach but depending on level of eliteness, ki starts with a physical change in physiological structures that can be measured scientifically i.e. punching harder. Proper biomechanics through breath control allows muscles to tighten in the diaphragm allowing a more rigid body allowing more force to travel through targets. This is similar to specialized breathing done during bench pressing weights or rowing where the breathing action is coordinated with the movement and breath is held so that the body is harder allowing more weight to be moved. This is superficial ki but beneficial to fighters.

Spiritual styles more or less worship ki as a connection to the divine and use meditative measures to establish a connection with the divine. They are trying to tap into that reservoir you referred to. Kiai is used in all Japanese martial arts not just striking based ones like karate, but it is also used outside martial arts and can indeed be found pretty much in all areas of Japanese life, especially those that are greater influenced by Shinto Buddhism.

Karate and jujitsu are heavily influenced by zen and buddhism. In Sanchin kata you are training to be centered and have a connection to the ground. You picture a "ball" in the middle of your body just below the navel and this is attached to the core of the earth thus making you "rooted". This "rootedness" shares likeness with seiza or zazen, there is this idea that when in seated position you are bound to the earth.

From a martial arts perspective mixing highly specialized arts with each other leads to compatibility issues and creates weaker arts. They become too esoteric. It is like mixing world religions and then claiming you have the best religion. It is just too agnostic. Chinese chi or qi is not ki and hara is not dantien. It would be like calling mormons baptists or protestants. Yes there are similar generalities but you would not consider them to be interchangeable terms as they have different pedigrees and take views and practice far apart from each other despite having common roots in a parent system.

What does kiai mean? The meaning of kiai has no formal definition. It's exact meaning is based on individual personal views. You can not "codify" kiai. In Japanese culture learning travels in a circles where when you master something you end at square 1 the beginning, a take on rebirth and starting anew. From not knowing what kiai is you will learn and that experience will shape your definition. When you have mastered what kiai means to you will be at step 1 supposedly ready to take in new knowledge (from the universe).

"Dantian is the 'Sea of Ki'" does not exist, you mean to say Dantian is the 'Sea of qi'. This is not appropriate to switch in an out of Chinese to Japanese as they are separate cultures with their own formalized opinions. It is like speaking "Spanglish". You are botching both systems and lacks harmony and misrepresents each separate style as one. Kung fu is not karate but mixing them and calling it "karate fu" is sure to raise eyebrows since this portmanteau would be seen as comical wordplay and nothing else.

Raising one's ki out of the body refers to Aikido and that is called bugei or "ghost technique". To take aikido and make it practiced in a physical way implies breath power or dragon power but there is no kiai To practice it in a spiritual way is more philosophical and more like a religious cult with meditation and ceremony. Taking this ceremony and habitual ritualistic repetition and combining it with tai chi it for entertainment purposes only. This would be similar to televangelism, you are commercialing the concepts for a broader mass appeal.

Etymological coincidence? No. More like etymological error. The Japanese took their alphabet from China. The two languages have similar sounds and words but vastly different meanings. The two share no connection except a distant past. Research how the Emperor of Japan created the Japanese language and how the Chinese misunderstand each other through speaking Mandarin and Cantonese. These three languages are not transferable in meaning.

Kiai on a basic level is yelling when punching in karate and karate only (maybe judo when throwing). It exists nowhere else (except maybe grunting while swinging a tennis racket or lifting heavy objects). Karate is dense and obtuse and does not go in for Chinese medicine. It is too simple and pragmatic to deal with fancy notions like that. Upper class sophisticated types are more into philosophy and drawing conclusions of the metaphysical with the physical world but do not engage with manual training and practical application of karate. Ki exists in kiai as energy but there is no kiai in ki. Qi is not ki and definitely does not have kiai in it or anything like it. Saying it does is a poor representation of our current understanding of physics.

If you are intent on creating a agnostic one world religion then the kiai is the third chakra, which is associated with sexual organs the loins and intestines, and to be conscious or aware you need insight from shape shifting reptiles would will teach you forbidden knowledge. The legendary Musashi is said to have defeated these creatures. The only battle he ever lost is said to be by the inventor of the jo (aikido weapon) who learned how to make it from the same creatures who come from the abyss (abyss means portal to another dimension but is represented as a whirlpool or other body of water). Physics cannot find these portals. As such demonology and spirit worship comes into play along with themes of lgbt. See wikipedia https://en.wikipedia.org/wiki/Kappa_(folklore).

  • 1
    Korean martial arts (e.g. Taekwondo and Tang Soo Do) feature a shout called a "ki'hap" ("Ki" meaning "energy", "hap" meaning "to join", "to harmonise", or "to amplify" - which overlaps with the Japanese word "ai" meaning "joining"), so saying that "Kiai on a basic level is yelling when punching in karate and karate only" is patently false. Mar 14, 2019 at 16:46
  • What korean martial art uses the term kiai? For ki to overlap is a western fore drawn conclusion. No korean would ever say"kiai" or use that tem because in Korean "kiai" means "ouch". Mar 15, 2019 at 4:17
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    As I said, Korean martial arts use the term "ki'hap" for the same phenomenon. If you're now trying to say that doesn't count because the name they use is different, then that contradicts your comment about swinging a tennis racket. (But, judo, aikido, kendo, Okinawan kobudō or even Taiko drumming all use kiai anyway) Mar 15, 2019 at 7:07

From a purely mechanical perspective, the purpose of a kiai in a punch is to force the abdominal muscles to engage, allowing for the transfer of effort (kinetic energy) from the legs and hips to the chest and arms in event of a punch (providing a backstop in accordance with Newton's Third Law of Motion), allowing more of this power to be delivered to the target (instead of pushing you backwards)

For a kick, you are using the abdominal muscles to help lift or swing the leg, using your torso as a counterweight (for an extreme example of the principle, consider how a cat is able to rotate mid-air to land on its feet) - done correctly, this replaces and supplants any benefit that styles such as Muay Thai get from swinging the guard-hand behind them as a counterweight.

As Joseph Malone mentioned, this is like the special breathing exercises done in things like weightlifting or rowing - using your abdominal muscles to join the kinetic energy generated from your upper and lower body. The word "ki", left untranslated, has picked up unwarranted mystical connotations, due to it being a homophone for the unrelated Chinese concept of "Qi"


Kiai means merging your energy. (Ki = energy, Ai = merge/join/blend/combine.)

The short story is that what you're attempting to do is, in the moment that you shout, you merge the ki throughout the body. In kiko (chi-kung) practice, this means circulating the energy from the dantien through the governing and conception vessels and out through to your limbs and back again. This is supposed to be done in a fraction of a second and completes when your fist strikes your opponent. At the end of the execution, you have ki being shot through your entire body, establishing a path from your fist down through your dantien and down through your feet.

It's a sudden release of energy which flows through and therefore joins the entire body together. Once the ki is connected throughout your body, the internal "pressure" of the ki is high, and the pressure is used to reinforce your strike. It's sort of like when you turn on the water through a fireman's hose. The hose will go from being limp and loose to being completely firm and immovable. That's what you're trying to do with your ki in your body in that exact moment your strike reaches its target.

So that's the meaning behind the the "ai" part (merging / blending).

In terms of shouting, this comes from Chinese martial arts, which in turn comes from Indian martial arts and healing practices (we're talking transmission between 600 and 1500 AD).

In Chinese martial arts, the yell is done to aid the sudden shooting of ki throughout the body. And different forms of Chinese martial arts do it differently, both in terms of what they imagine they're doing with the ki in their body and the sound they make. Different sounds have different purposes. There's even a different sound for each of the 5 elements of traditional Chinese medicine and martial arts. There are books written on this subject, and it can get fairly involved.

Don't get me wrong, though. I'm not promoting the theory. In fact, I don't believe in any of it personally. I just wanted to share what I've picked up over the years. The rabbit hole goes down pretty far, if you want to follow it.

Hope that helps.


From Hapkido by Marc Tedeschi while interviewing Grandmaster Han-Jae Ji, "Ki-power is adrenaline only? Yes. Adrenaline only. There is no energy out there in the universe that we bring into our bodies? No. Why does virtually every book written on Eastern thought state something quite different-energy is absorbed from nature, the body possesses three tanjon regions,etc? I don't know. The human body has everything inside it to make Ki-power. It's not from the outside. It all comes from the inside."

I misspoke earlier. When Japan conquered Korea native arts were banned. Koreans copied shotokhan military karate and it helped influence tae kwon do's development. This mixing of styles lead from a departure of internal martial arts to more external martial arts, the hard styles. Koreans favor defense over offense while Japanese favor offense. The Japanese train to be invaders. The Koreans started emphasizing defense since they felt insufficient in that area because of being invaded. They wanted to be prepared next time.

The idea of mixing world religions ties into ki as a western occultic practice. It is not martial science. Occultic practices, like voodoo, say that energy comes from god or a balance between god and the devil. The story of the kappa inspired a real assassination of a Japanese lord who was sitting on his toilet and was stabbed in the anus by a spear. The assassin came from the abyss.

Chronocidal is right when he says there is an overlap. Styles were overlapped because Koreans choose to copy the style that had defeated them but they took their training to weird places because they had to train in secrecy. As a result there understanding of kiai is not accurate and kiai only exists in Karate. Ki as a generic term for energy is universal but "kiai" only exists in karate. In that sense "hapkido" and "aikido" as eclectic blended styles share the same parental roots in daito-ryu aikijutsu, there are similarities. For etymology I do not know how accurate you want to be. If you want to study history then etymology matters. If you want better martial arts then you should focus on physical training as too much talking interferes with that. Most students undertrain. Deeply researching history as a librarian comes when you are too old to fight. At that point you become a war and history buff.

If you are using the term kiai then you are claiming to be a Japanese karate student or at the very least you are paying homage to Japanese styles. Ki'hap is not kiai. It would be inappropriate to use the term to refer to Korean styles. It is confusing world cultures and is insensitive but more over it misrepresents the martial art styles and tries to draw comparisons where there isn't any. Most of it is political but the rest deals with combating fraud. If I made a style I would not want someone teaching incorrectly and embarrassing me and making me look bad. Sometimes pedigree matters. I'm sure American Tae kwon do schools use the term kiai. In a mixed martial arts world where everything is homogenized cultural subtlety is lost. If you just wanted to fight then just mix it up. If you wanted historical accuracy and preservation of the truth then that would affect time spent on learning to fight and ability but you would be telling the truth. Qi versus ki and kiai versus ki'hap almost boils down to quibbling over semantics. These are arguments I wish to avoid however is should be stated that the terms are different and should not be interchangeable. It is like using an ordinal indicator as a degree symbol just because it looks similar. It is similar in cosmetics only but it's function differs.

Yes all styles may use ki as adrenaline to move harder or faster. I am unsure how ki'hap generates force but it is different than kiai. It is lower. Kiai is faster and lighter. "Kiai" means speed and power and you are trying to blend, roughly, kizamitsuki and gyakutsuki together. This makes a speedy jab and a strong cross combo. This is repeated and you get sanbon, yonbon,gobon which is 3,4,5 hit combos. Koreans do not punch like this at all and do not think like this at all. Their thinking is entirely different and does not focus on this strategy or method of producing force. That is not how they fight nor their views on the martial arts. I do karate and do not want to speak for them as it would marginize them.

On another note there is the western concept of the alpha zone or "being in the zone". This refers to increased levels of alpha waves produced by the brain causing increased focus and mental acuity. Alpha waves differ from beta waves and delta waves. Alpha waves are rare. These are naturally occurring metrics that can be measured by science and have although research is quite limited on the subject.

Professional athletes and martial arts claim to benefit from these alpha waves and that time slows down allowing them to make quicker moves or decisions. They can act without thinking and things happen automatically. This is related to the samurai concept of "mushin" or "no mind" where they react on their training and honed instincts instead of thinking about it.

Please forgive any oversights. This is a complex issue. I can not explain everything in such a short space.

  • I don't know that I agree with everything you say, but I appreciate the breadth of the answer. Mar 15, 2019 at 10:00

A kiai comes from the hara or dantian in the same way that a singer projects using their diaphragm. You can point to a physical place on your body and say this is where the hara is, or this is where the dantian is, and this place is roughly where you feel pressure when your diaphragm pushes down into your abdomen as you inhale deeply. In this limited sense, a kiai comes from the dantian because it comes from the lower belly area.

The dantian is primarily an energetic concept, not a physical one. The location does correspond roughly the center of mass, but the basic idea is that once your body and mind are sufficiently relaxed and concentrated, you will feel the dantian.

The martial arts I have encountered (taiji, xing yi, and bagua; the so called internal arts) that believe a direct experience of the dantian is important do not use a kiai. Let me try to explain why the loud, explosive kiai does not make sense in the internal arts context. There is a taiji concept that you should attack when your opponent has spent their old strength and not gathered new strength, for example when they have punched, but not yet reset their arm or stance. Conversely, when you attack, you want to minimize (ideally eliminate) the window between when you attack and are ready to attack again. A person executing a kiai enlarges this window and provides an unmistakable verbal cue for when they are expending their strength.

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