When I see people doing forms, competing, or breaking blocks of concrete or wood with their hands, they are always vocally expressive in what they are about to do. What names does this "shouting" have and why is it done in techniques?

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    Although all the other answers are valid, at least in TKD, one of the best reasons for kihap is to help you take hits better. Getting kicked in the stomach silent is a thousand times more painful than getting kicked while doing a kihap. When we practiced with wearable targets, we were taught to kihap with each hit for this reason. Commented Jun 3, 2015 at 2:52
  • Some studies even suggest that shouting when executing a strike can make significantly more powerful.
    – LemmyX
    Commented Jan 13, 2020 at 3:22

15 Answers 15


The shouting, called kiai, has multiple purported purposes. I would note that I'm posting these not out of a necessary belief in them, but out of explanation as they were taught to me:

  1. The forced and trained rapid exhalation of breath. This can be used as both focus (by focusing on breath, one is less inclined to focus on the fear of failure when faced with the thought of breaking something apparently hard), and as a method of rapidly exhaling carbon-dioxide from the body to increase oxygenated blood flow to the extremities.
  2. The external (outer or omote) harmonizing of ki energy (気合 - kiai), as opposed to the internal (inner or ura) harmonization of ki energy (合気 - aiki). [NB: This is not something I believe, so this is best left to someone else to explain familiar with the concepts.]
  3. The expulsion of intent. Kiai acts as a declaration of your fighting spirit, your internal desire to prevail in those circumstances. This can be for intimidation, self-reassurance, rallying (the war cry was essentially a form of kiai), etc.

Something that many people may never learn: the kiai need not be loud. In some arts, the kiai is taught as a voiceless projection, called kage no kiai.

In addition, some arts offer specific forms of kiai, for example (from the Bujinkan; I have no record from which school, I simply have it in my notebook as kihon, but the proper term is more likely kotodama)

  • ei! - A growling shout, meant to accompany an attack; intended to force the opponent to lower his guard momentarily.

  • toh! - A heavy shout, meant to accompany a counter; intended to make the opponent believe he has left an opening.

  • ya! - A boisterous shout, meant to respond to a series of blows; intended to dishearten the opponent, making him believe that you believe you're already victorious (may tie in to folk beliefs that a battle is decided the moment two adversaries first see each other).

It's said the kage no kiai taught in the Bujinkan is a harmony of these three shouts, voiceless or in a low hum, assuring the warrior of victory. This might be viewed as a form of self-assurance, helping to maintain a form of inner calm or mushin.

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    Excellent answer IMO. I'd like to add a small elaboration: in traditional styles initially the kiai is taught to beginners to help promote ki flow, for the more advanced practitioner the different types of kiai are used to change the nature of ki flow.
    – slugster
    Commented Feb 7, 2012 at 22:02
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    @slugster: Appreciated. I have issues with explaining things in metaphysical terms, which is why I stayed purposefully vague in that respect. Psychology I can handle; metaphysical energies just make me uneasy, as I feel they tend to be used as a copout.
    – stslavik
    Commented Feb 7, 2012 at 22:10
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    NB: An edit placed "Kotodama" as a "proper term". Unfortunately, it did so attached to a sentence tying the term to the Bujinkan by a semicolon. I have seen Kototama in reference to buddhism, but have never seen the term in any notes or densho for the Bujinkan, and would not claim it "proper" in connection to any art without first confirming that against densho. Kototama is a broad term for any "word of power", the belief that an utterance can have supernatural effect.
    – stslavik
    Commented Jul 26, 2012 at 16:11
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    In the context of your point 2) and to climb a bit lower on the philosophy scale, it is perhaps worth pointing out that the Japanese 気合を入れる kiaio ireru, literally "to put kiai into it" means "to motivate oneself, to push oneself forward," and is an everyday word. So I propose this theory: a teacher said "push yourself!" and their students took that a bit too literally … :)
    – tobi_s
    Commented Jul 6, 2019 at 10:18

Depends on the style, but for the purposes of most Japanese martial arts, the "shouts" are Kiai and serve a couple different purposes:

  1. Contracts the diaphragm and chest which can allow you to take a hit better.
  2. Puts extra "energy" behind the strike as it causes you to focus on the moment of impact.
  3. Shows "spirit" when in competition.
  4. Shows where strong strikes would be during kata.
  5. Can catch opponents off guard if they are anticipating it or don't know what to expect.

Depending upon the situation they can also act as a battle cry in some ways but I haven't heard that explanation for them given at the dojo.

  • 5
    Our sensei explained that it also allows him to be sure you are breathing, as a fair number of people when starting out seem to have trouble remembering to breathe throughout a technique.
    – eidylon
    Commented Feb 7, 2012 at 21:05

A Kihap is basically a battle cry, carried over into modern times. But there are actually some very positive benefits.

  1. It strengthens your core by tightening your abdominal muscles. This translates into more power in your motion and increased defense. The Kinetic Chain, also called Kinetic Linking, is the way your legs can pass their power through your torso and into your arms. To be effective every part of the chain must work as one unit.

  2. It makes you breathe. Heavy physical activity requires energy, the cellular process in your body to generate energy (ATP or Adenosine Triphosphate) requires oxygen. There is another process that doesn’t require oxygen, but it generates much less ATP.

  3. It can help you focus. With lots of repetition your mind and body can be programmed a certain way. National Geographic has a show called Fight Science; in one episode, SWAT team members could control their heart rate even with highly elevated levels of adrenaline.

  4. It startles your opponent. To me this one is a side benefit, but still valuable. It’s possible to avoid the fight completely by dropping back and letting your kihap out; might make them think twice.

It doesn’t really matter what sound you make, you can achieve benefits 1 and 2 by remembering to breath properly when striking. Some people make a "Tsst" sound when striking; as long it comes from the abdomen it should still provide benefits.

I don’t believe letting out a long blood curdling battle cry is beneficial when striking. Your kihap needs to be very quick, one, maybe two syllables max. The reason I’m saying this is because if you have a long kihap when striking your jaw is in a vulnerable state, it’s open. A tight jaw will help guard against dislocation or outright breaks.

Another negative might be that you signal your intent if you kihap too soon in your strike against a trained opponent, or signal the end of your attack. For example, in class we kihap at the end of the pattern, which means the attack is over. A large component of fighting is information warfare, you're reading your opponent's weaknesses, trying to conceal your own, and conceal your intentions.

So there is something to this ancient activity. It doesn’t summon the power of the spirit world to let you shoot a fireball out of your hands, but it gives you more power, a better defense, and might scare your opponent off.


There are two kind of shouts, long and short ones.

Long shouts:

The shouts you're referring, Kiai, are a way to increase intensity, and give the practitioner an easy meaning to give a direction to his/her KI.

When speaking about Ki direction, do a favour to yourself, and refrain to think in esoteric terms.

Ki direction really means direction of everything: mind and body intentions. A shameless and (really) strong scream practically forces your mind and body to focus on one direction and one thing. It's physiological.

A cheap trick to know what we're talking about is to look at something in front of you and scream very strongly at it and then turning your head and screaming very strongly at something in another direction (say 90° left). Pay attention to actually look what the objects/persons you're screaming at.

When you do that strongly and shamelessly enough, you should feel subtle differences in your body position. That is: the scream effectively directed your body here or there.

Summing up: it's an easy (when done right) way to achieve something otherwise difficult.

Since it works when you're screaming hard, though, it is difficult to practice in many environments. If you're a novice and screaming less than your maximum then you're doing it wrong and it will serve no purpose.

Short shouts:

They're just a mean to contract the diaphragm, and coordinate breath and body actions to improve breath endurance and marginally augment the power of the strikes.


There are a few reasons that they claim is why they do this:

  • They claim that it may scare off the attacker
  • It is supposed to alert other people
  • and lastly, it is supposed to put more power behind your technique

I can understand the mentality behind this, if your attacker doesn't want to attract attention, shouting will attract attention and may scare them away.

When it comes to the last one, I can understand that too. it does in fact help the power of the technique. Personally though, being that I do Krav Maga, and ICS, I prefer using a technique where you breathe out quickly with each punch making sort of a quick ssshhh sound. This particular technique is also used in MMA, Muay Thai, Boxing, and other similar fighting styles.

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    Your ssshhh sound is still a form of kiai - it is normal for people to develop their own personalized kiai and for it to change depending on what they are doing.
    – slugster
    Commented Feb 7, 2012 at 22:21

In addition to Rob Z's answer, kiai force you to breath. This is a good thing, especially when you are in a randori/competition situation where one tends to hold their breath.

  • Yeah but that's such a low-level answer... If the kiai is actually a "remember-to-breathe" training for your style, I argue your style is lacking a breathing training :-)
    – Anon
    Commented Feb 7, 2012 at 15:40
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    We don't tend to use kiai at all and certainly would get a stern look from the judges if we used it in randori. It never has officially been described as a "remember to breath" technique but does serve as one nonetheless ^_~ Commented Feb 7, 2012 at 15:50
  • Quite a good point :)
    – Anon
    Commented Feb 7, 2012 at 16:06

All the answers about aiding concentration and releasing your inner power are good, but mostly for striking moves.

On the Judo side of the house, the Kiai mostly manifests itself as a loud and determined grunt. That said, I have heard a few roars during some particularly impressive standing work ... generally where a smaller player gets a larger opponent airborne. A roar like that is often followed by standing applause from the spectators if the technique worked!

  • The release of inner power can be applied to any movement, not only striking moves.
    – Anon
    Commented Feb 11, 2012 at 17:36
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    True. I don't think that I was saying it couldn't be. More indicating that it's manner of expression was different. Commented Feb 12, 2012 at 0:31
  • Often kiai in Judo is to convince the ref/judge that you were doing the move so they don't score something else for your opponent.
    – Robin Ashe
    Commented Jul 26, 2012 at 3:41

This question is too broad to give it an exaustive answer, because (as you can see from the answers) each martial art gives its interpretation of the kiai.

Speaking of Karate Shotokan, the kiai is performed to stress the power on a technique (for kihon and kata) and to intimidate the opponent (for kumite, and also for validating a successful blow during tournaments).

It is worth noting that the kiai is not performed by "shouting" (after some shout in succession you lose your voice); but instead is performed by a powerful contraction of the abdomen.


One of my partners this weekend reminded me of another reason that it is important to exhale during execution of a technique. If you are hit, or hit the ground (take a fall) while holding your breath, you're going to (a) hurt more and (b) take longer to get up.

I can't quantify the difference, and I would recommend against the experiment . Sadly even though I remember (not pleasantly) the falls I've taken while holding my breath, I still have to work on it every couple of years - it is a bad habit that comes back.

  • Breathing helps you be relaxed thus you will bounce more than crash during break falling. Commented Jul 30, 2012 at 10:46
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    @Sardathrion My understanding is that it goes beyond that, namely, to the method described in this Bullshido thread: "Envision a balloon filled up, held closed by your fingers, still untied. Lay the balloon on the floor and stomp your foot on it. If you hold your fingers tightly, the balloon may burst. If you keep your finger grip loose (breathing out as you break the fall), the air will naturally be expelled, and the balloon is fine. (I am not in any way suggesting that your diaphragm will burst, it's just an analogy.)" Commented Jul 30, 2012 at 14:40

I'd say it's a waste of energy if you aren't using it to scare an opponent. When striking, kicking or blocking it is important to exhale to relax the body so that you can get more power into the strike. This should however be done more or less silently.

People bench pressing also does this to get more power in to the press, most of them without screaming or making to much noise as you want the force to go into your arms not out through your mouth.


Besides the inner and outer manifestations of power and focus which are mentioned in the other answers, the yell also has other uses which haven't been mentioned. In two styles, the kiai (japanese) or kihap (korean) have context in sport rules:

In Kendo, the attacker must yell the target: men (head), kote (wrist), do (side, waist, body), and tsuki (throat)

In Kumdo, the attacker must yell the target: mori (head), sun-mok (wrist), and hori (side, waist, or body)

When striking, you must yell the attack. Failure to do so, or yell the wrong target, means the attack does not count. If you do not yell it loudly enough, the judge may not hear it, especially if your opponent does it loudly at the same time as you.


If one has sufficient vocal training, and can project ones voice, this technique can indeed be used to disrupt the concentration of a many opponents.

Here what I mean is being able to vocalize with sufficient direction and volume that the opponent can feel it in their inner ear. This is particularly effective in a closed space, which creates resonance at certain frequencies—trained actors know how to "tune their pitch" to a given room for maximum resonance, and it becomes an unconscious reflex. (In my school, because of my vocal training, my shouts were acknowledged as being more effective than that of other students. When we had a strong fighter who also studied opera, he was likewise able to disrupt attention with a shout, which provided some validation.)

I've never seen value in using with with a strike, but instead, before a strike because you can often get people to wince, which creates an exploitable advantage.

You can compound this effect by sometimes striking after a shout, sometimes not, to mentally unbalance the opponent, since deception is the core of strategy!


A proper 'spirited yell', or 'power exhale' or what-have-you actually is meant to activate the very core muscles, the abdominal band, and the tantien, one of the three main chi centers and the place where the body stores chi). This allows you to release more energy and, well, be successful in your technique. When breaking boards, it's useful so you don't hurt yourself. In a competition, it's to impress the judges, so forget that. In a form, in practice, you are training yourself for specific ways to release this energy (kick, uppercut, elbow, etc).

  • Some competitions take into account spirit and energy in judging your form. The sprited yell will manifest physically in your technique like you said which shows who you are as a martial artist. If you want to perform at your maximum capability, why would you hold back in that case?
    – user15
    Commented Feb 7, 2012 at 15:33
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    Oh man, I wish I had been to competitions where real skill was taken into account! Maybe it wouldn't have disgusted me.
    – Anon
    Commented Feb 7, 2012 at 15:39

Its as simple, go bk to Bruce Lee, the reason behinf the shout of a heavy aggresion of anthem that is called in certain arts is to use your individual, toatal force as vital as possible, with the breath, that is in the very point of the positioning attack, the as you phrase scream, is a vital use of internal and your physical force in the point of skill being used , example when a person scream ,what is he using on his internal emotion force?Got it.... Maximum force in a vital but positive extreame attack. This skill is only used, if your opponent is coming towards you in a killing motion of moves or the fight has come to a deadly point where by your life is to be safed..


What i Know is - human brain receives one signal at a time. We take our strike as a light signal and shout as a sound signal. If the brain received sound signal the hit will serve more dangerous to the opponent. Just like a hit to a person who is not alert towards the move, strike becomes more dangerous than to whom who is aware of the strike.

Secondly it is a natural process producing sound force to pull or push a more heavy weight, we use the same force to deliver the strike.

Thirdly animals scream, shout & Grunt naturally when they are scared and try to scare the opponent by high sound.