What Does It Mean When Somebody Shouts ‘Oi’ In Muay Thai?

If you have ever watched a Muay Thia fight in person, or if you have seen some of the many videos of this fighting style online, then you have probably heard the fighters shout something throughout the match.

What does it mean when somebody shouts 'Oi' in Muay Thai

You may have thought that the fighters were shouting “Oi”, but they are shouting “Oh-Way”.

Following the fighter making this noise, you will hear a loud thud as the fighter makes contact with the person or a heavy bag if they are training.

But why do they do this? You might think that they are making the noise to show off how strong they are, similar to how gym bros grunt loudly as they lift heavy weights.

The grunts and groans that are employed in Muay Thai, on the other hand, have a purpose more than just for show.

When they launch an attack, they are executing a very specific maneuver.

A scream, grunt, or cry that is utilized in Japanese martial arts, including Muay Thai is referred to as a “Kiai” or an “energetic shout.”

The fighters in Muay Thai make these noises at the moment of impact to “stiffen” their bodies, which amplifies the impact force of the strike.

The ‘Kiai,’ is a tried-and-trusted way to swiftly raise the destructive power of your punches. But how does raising your voice make your punches more powerful?

Keep reading to find out!

How Does The Shout Boost Punching Power?

To fully understand how shouting can boost the power behind the punch, we need to look at a few basic scientific terms to help us to understand.

In this case, we take into account both the effective mass and the double-peak muscle activation.

When we talk about effective mass when hitting, what we mean, in a nutshell, is the transfer of momentum throughout the body and onto the target.

At the time of the impact, the only way for the body to transfer as much momentum as possible is for it to be completely rigid.

Soft structures will flex when they come into contact with hard objects, which results in a decrease in their effective mass.

The process of the implicated muscle groups in a strike becoming activated right before or during the initial phase of the movement is referred to as “double peak muscular activation.”

Following that, the muscles relax, and then immediately before contact, they begin to contract once more.

So what causes this to happen?

Because the relationship between force and velocity is inverse, it’s not possible to generate a substantial amount of force by trying to deliver a blow as fast as you can.

This is because the link between force and velocity is a one-way street.

When someone makes an effort to hit with the maximum amount of force possible, the velocity of the impact that they deliver is greatly lower and slower.

As a result of the double peak muscle activation, the fighter can simultaneously optimize both the force and the velocity of the punch that they are throwing.

So now that we have all of the science explained, you may be wondering how exactly the Muay Thai shout comes into this. It turns out that what produces the second peak in muscle activation is the energy scream.

To put it simply, Muay Thai fighters can stiffen in the very last possible moments before the blow makes an impact by shouting “OH-WAY.”

This increases the effective mass of the stroke and, as a result, the force with which they hit their opponent.

The energy shout impacts how rapidly you can create force. This ability is measured in terms of how much force you can produce.

Because of this, you can make the transition from relaxed muscles during the strike to activated muscles upon contact as rapidly as possible, which increases both the impact force and the velocity of the strike.

Here is a workout that you can complete without having to try Muay Thai fighting for real. Try to exhale from your mouth as rapidly and powerfully as you possibly can.

When you brace your trunk, you should get the sensation that you are about to be struck by someone or that you have just sneezed.

What you will feel is the same sensation that the Muay Thai fighters feel when they do the energy shout.

Are There Any Other Benefits To The Shout?

What does it mean when somebody shouts 'Oi' in Muay Thai

When you practice the energy shout, you are not only increasing the force with which you strike, but you are also learning to regulate your breathing. This is extremely beneficial.

While you throw a strike while exhaling, it will be easier for you to remember to breathe, which is very crucial when you are throwing combinations.

If you don’t breathe while you are striking, you will run out of breath much more quickly because you will have to try to catch your breath as your opponent is coming at you.

there’s some spiritual logic behind the Kiai shout as well. Kiai is an expression of your will to fight. It’s used to serve as a call to arms for you.

It’s an expression of the inner drive you have to be successful in the fight or struggle you are in, and it’s a manifestation of that desire in the external world.

Can You Make Your Own Kind Of Energy Shout?

Yes, you can. During the process of developing your unique energy shout, it’s essential to avoid trying to force a certain sound on it in any way.

If you make use of whatever is most natural to you, you will end up with a shout that is uniquely yours.

When it comes to making contact with something, there’s no such thing as an unpleasant sound.

Even if you start off feeling apprehensive, you’ll notice that even during the most intense pad training or heavy bag exercises, a Kiai will flow out of you easily. This is true even if you feel like you have no control over your body.

As your body starts to tire, you will most likely grunt or shout out as you put in the additional effort necessary to maintain the power behind your punches. This is because you will have to work harder.

You have at this moment found out your one-of-a-kind energy shout. Congratulations!


Even while it could be a lot of fun to shout out loud when performing pad work or training with the heavy bag, it’s still a good idea to build up some solid habits in preparation for when you go up against an opponent.

You put yourself in a vulnerable position when you attack with your mouth wide open.

Instead, practicing Kiai with your teeth firmly pushed on your mouthpiece ensures that your jaw and neck remain straight, allowing them to better absorb any force that may come their way.

Christopher Anderson
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