What is Kiai?

It is a word that can be heard in traditional Japanese martial arts classes around the world. This article looks at why martial artists shout it, what it actually means and why it is more complex than a simple shout.

The word Kiai is comprised of the two Japanese Kanji - Ki (気) and Ai (合). Let's take a look at their meanings...



Ki - is a symbol of spirit, mind, energy, force


Ai - is a contraction of the verb 'awasu' which literally means 'to unite'.


Evidently the word Kiai means 'Spirit United'.

It is important to note that the key character is Ki (気). Those of you familiar with east asian language will note that the similarity Chinese character Qi (氣) - which has the same meaning. See our article - What is Chi?. However, the Kiai is more commonly associated  martial arts styles originating with Japanese / Okinawan due to their 'straight-line' methodology rather than the circular / soft styles of China. Nonetheless, Korean styles also have their own form of Kiai, known there as 'kihap'. You will hear this as a loud shout in Taekwondo simultaneously when performing a hard striking technique or when preparing a fighting stance before sparring.

Martial artists from the east believed that a Kiai was a method of focusing their Ki during sudden bursts of energy. It is thought by some that the second character of 'ai' is used as nothing more than a vocal expression to channel that energy from the individual.

Defining Kiai in context

As most martial artists will appreciate, the Kiai is a little more complex than simply defining the composition of it's hereditary Kanji. I particularly feel that Grandmaster Robert Trias (a pioneer for Karate in the US in the 1940's) puts it in excellent context:

Robert Trias

"The kiai must be recognized as the ultimate unifying force that brings the body, mind and the opponent into a focused, controlled alignment, with harmony between self and the opponent. The actualization of this potentiality of time and space at one point, physically, and while releasing spiritual potentials, determines the way of development and brings to consciousness an inexpressible awareness of life itself."

Grandmaster Trias further explained that the kiai must be heard at the same time as the delivering of a technique with the philosophy in mind that this helps focus all the body's energy into that one single moment, usually at the exact point of impact of a strike. Furhter it may even disorientate the less hardened opponent from his own structure by making him freeze, startle or become distracted.


Benefits of the Kiai

  • Breathing - when faced with danger as the adrenaline rips through your blood vessels, it's common that we forget to breathe, or fail to breathe sufficiently to cope with the sudden increaase in our heart rate and quiock depletion of oxygen through it's passage into our muscle fibers. Kiai can actually remind the body to breathe.
  • Added power - if the Kiai is executed properly, the muscles around the stomach are tightened and it has been said by ancient asian physiologists that this allows energy to be transferred from the abdomen to the peripheries of the body including the elbows, knees, hands and feet. Watch the athletes at the Olympic games, javelin, discus, hammer throw, shot put - they all do it, because they know it gives them a boost in their short term power output.
  • Distraction - as mentioned, the sudden yell can distract the opponent, startle him or even cause him to falt on his own techniques. A trained fighter can instantly take advantage of a gap in the opponents concentration.
  • Psychology - it's been happening for millions of years, it's part of Charles Darwin's theory of the survival of the fittest and we see animals perform it on nature shows - 'the war cry'. Why do they do it? It gets the blood pumping and puts the brain into a mental state of higher awareness and also gives the opponent a second thought about going into combat with someone who means business!

How to Kiai

Executing a Kiai is not to actually say the word itself. In fact a very common sound made during a Kiai is 'toh' or 'yah'. Is it important to note that a sound is not essential, it is the breathing and contraction of muscles within the abdomen that is the critical factor to gaining the benefits of the additional power. Ususally highly experienced practitioners do not make an obvious vocalization when performing the Kiai, however it is recommended that beginners do vocalize their Kiais as it helps them to perform it correctly with the use of their abdomen muscles.




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Karate Kitty's picture

Well, now it makes more sense and clears up alot of questions I have had about Kiai! I mean I do Shotokan Karate and it is tought to us to vocalise it when doing certain training techniques and it is also relevant throughout all of our Kata. I have wondered why we vocalise kiai at all during kata etc. Next time when I shout out kiai I will know why I am doing so. With a new understanding and focus and also it has much more meaning to me now. Thank you for yet another informative and usefull article. KK
cris donovan's picture

good piece Ashley, i gave a class on it for our juniors last week and i wish many of them were old enough to come to this site and read this just to reinforce what i said..maybe they will in a while as most are between 5-9 at the moment, but everything you said is what they need to know...and a few adults too! well done
darklight's picture

they do the same thing in krav maga, although im not sure if it was just my teacher adding into the art, or it was a part of krav maga