By: Stephen Whiffen, 5th degree black belt, Okinawa Seito Karate-do Yoshinkan Dojo


In this article, I will present a brief treatise on the basic principles behind developing power as currently taught at the Okinawa Seito Karate-do Yoshinkan Dojo.

First, it is necessary to establish a definition of power as it relates specifically to budo (classical Japanese martial ways). When most people think of power, they think of raw, physical strength. In Japanese, this is called chikara. A person who possesses chikara is physically strong and has a high level of muscle fiber development. For a karateka (practitioner of karatedo) to strike with chikara, therefore, infers that one is generating power by relying chiefly on brute strength by tensing, mainly, the muscles of the upper body. The whole body is not usually involved in the movement as the technique may be powered solely by a specific body part, such as the arm and/or shoulder. Even though a karateka punching in this manner may have a very strong arm, the inherent power in the blow is restricted to the limited strength of that body part. In addition, the tensing of the muscles may not be specific to the action of the motion (ie. the technique being performed), and there may be a general tensing of all muscles in the upper body, including antagonistic muscles and those not used in the technique. It is a general perception among non-practitioners of budo that a muscular individual can generate a lot of power by using only chikara. While this may be true, there are several serious drawbacks for most students of budo if they are to rely on this method, particularly in terms of combat effectiveness. First of all, not all of us are built like the Incredible Hulk, so it would take years of weightlifting to achieve this level of physical strength (which will, at any rate, inevitably wane as the years advance upon us!). If chikara was the only way to generate power, the muscular individual would always triumph, which we know is certainly not the case. Second, someone who is punching with chikara is usually very unbalanced, which puts a karateka at a distinct disadvantage in an actual confrontation, especially against multiple attackers. Maintaining balance is crucial in any combat art, and indeed in all aspects of life.

It is obvious that any movement of the human body requires at least some muscular contraction. When performing martial techniques as well, there has to be some muscular activity inherent in the execution of the movement. Hence, a bare minimum of chikara is necessary. But in order for a karateka to develop the incredible power that top level masters can easily demonstrate, it is absolutely imperative, at some point, to let go of chikara; to, in essence, achieve a state of relaxation in the upper body throughout the whole of the technique where all tension is dropped through the hips and into the lower body. All movements and techniques are smooth and fluid, and there is a bare minimum of muscle contraction in the trunk and limbs of the upper body. The Japanese word for this type of relaxed power is iryoku. The degree of iryoku that can be generated, as opposed to chikara, is not dependent solely on the muscular strength of individual body parts. Nor is there unnecessary tensing of muscles in the upper body. Iryoku as used in Okinawa Seito Karate-do is true power that can be generated by both the coordinated effort of the mind and body as well as the relaxed connectiveness of the whole body working in unison.

Iryoku in Detail

In contrast to striking with a tense upper body (ie. using brute force) and an unbalanced lower body, the whole precept behind iryoku is to keep the upper body as relaxed as possible and to strike with the body as one unit, keeping particular care to remain balanced and rooted. Being relaxed is a key point, as is maintaining a stable stance. When executing a martial technique, contraction of any muscles not directly involved in the movement inhibits the potential power that can be generated. In addition, tensing of auxiliary and striking muscles at ANY point throughout the technique (including tensing the muscles at the point of impact) will invariably invoke the use of chikara, thus restricting the flow of energy to the target and ultimately reducing the level of power which can be generated.

When true iryoku has been achieved, the amount of power one can generate is not dependent solely on the size of muscle fibers in each individual body part alone. With proper training, even karateka of advanced age or small stature can achieve devastating power. True masters of traditional Oriental combat arts, many of whom are in their 60’s or older, can demonstrate this easily on practitioners a third their age who rely on chikara. Obviously, other factors besides brute force are coming into play here. This is often a difficult concept for non-budoka, and even many practicing budoka, to appreciate as it goes against the common notion that muscular strength equals power. Hence the large numbers of budoka who weight-train in the pursuit of developing chikara, or muscular strength. The concept of iryoku does not readily appeal to the intellect, and the martial artist must train in the correct manner repeatedly until iryoku is finally achieved before it can be clearly understood.

Iryoku is not some mysterious force or psychic phenomena. Anyone who has trained consistently in a manner that will facilitate the development of iryoku will gradually have access to the full potential of power that the human body can generate. The process by which iryoku is manifested requires the budoka to incorporate the following two elements into their daily training:

  1. Learn to coordinate the entire body so that it moves as one complete unit, and
  2. Learn to unify mind and body.

This process is ongoing and requires many years of focused practice, but eventually true iryoku will start to appear and the budoka will tap into the latent power which exists in all of us.

Power Training

The specific practice methods and training pointers of the Yoshinkan Dojo to develop iryoku will now be discussed in detail, keeping in mind that consistent training is the key to gaining an understanding of these concepts.

1. Coordinate entire body

To coordinate the entire body means to perform a technique in a manner that will utilize the connectiveness of each part of the body to its maximum effectiveness as one whole unit. In other words, the power of the whole body moving as one is greater than the sum of the individual parts (ie. the arms, legs, etc.). The key here is the connectiveness of the body – the movement of all limbs and the trunk coordinated together to facilitate the fusion of power behind the technique.

In order for the whole body to move as one unit, karateka have to think of striking with the body. This is a crucial point – students must think of striking with the body, not merely with the part of the body being used as a weapon (ie. the fist, knifehand, elbow, etc.). Most beginners will throw a punch or block and attempt to focus all their power in that part of their body. However, by doing this, the power behind the technique will invariably be done with chikara, not iryoku. For iryoku to appear, one must forget about the “weapon” and think only of striking with the body. In other words, the power originates from the hips in response to the coordinated effort of the body and extends naturally to the weapon. The hips play a vital role in the process because this is where the tanden (or hara) lies. The tanden is basically the point of the body’s center of gravity. It is located approximately 2 inches below the navel and is regarded in most types of budo as the center of coordinated energy in the body. In the Yoshinkan dojo, all techniques, even kicks, originate from the tanden. This is the case when shifting the body in kumite as well, since the direction in which the karateka moves is usually determined by the orientation of the tanden. Because of the in-close fighting strategy of Okinawa Seito Karate-do, the tanden will usually face the direction one intends to move. To strike with force, one should commence the movement from the tanden and think only of striking with the body, even though in most cases it is actually the “weapon” that will be making contact with the opponent.

As an example, let’s examine a basic chudan oizuki (middle lunge punch) in detail. In classical karatedo, the punch usually starts from a resting position at the hip, the “chambered” position. It will then shoot forward, usually as the karateka is moving into a zenkutsudachi (forward stance) with the forward hand performing the technique. At the Yoshinkan Dojo, in order for students to learn to punch from the tanden, the chudan oizuki is done as follows. From a zenkutsudachi, the rear foot starts to move forward by skimming the floor and the hips are kept parallel to the floor. At this point, even though you are stepping with the foot, you should feel as though your body is being lead by the tanden. In other words, move forward with the feeling that someone has tied a belt around your waist and is pulling you forward. The punching hand is positioned in the “chambered” position at the hip and the non-punching hand is held out (to be later withdrawn). By keeping the non-punching hand extended until the punching hand leaves the “chambered” position, you will feel a slight and natural stretching of muscles on that side of the body along the shoulder, side and hips. The hips are basically kept in a straight line throughout the movement. Don’t, however, exaggerate this stretch by consciously pulling back the punching hand at the hip as if it was being “cocked”; this puts too much upper body, and hence chikara, in the technique. Just before the leading foot touches the floor to complete the forward movement, the punching hand leaves the hip to initiate the punch and the extended (non-punching) hand is withdrawn. The punching arm is very relaxed and no conscious effort is made to “power” the punch forward. As the leading foot touches the ground and the stance is immediately rooted, the punch has been about half completed and the tanden is moving forward into the stance at precisely the same time. The timing of the punch here with the forward momentum of the tanden is critical in order to maximize the power coming from the tanden, which has now climaxed from the coordinated effort of the whole body (legs, hips and upper body working in unison) At a more advanced level, the student can be very close to the opponent as the punch is initiated to prevent it from being blocked. When this punch is done correctly in a relaxed manner, it is extremely difficult to block in a hard fashion. Maintain good posture throughout the technique so that the hips are square and the upper body is not leaning forward. The upper body remains relaxed from start to finish, and even at the conclusion of the punch, there is no tension in the arm or forceful stopping of the fist as if to “focus” the power. The intrinsic energy of the body will extend more fully if the arm is kept relaxed at the end of the strike.

In order to practice the technique as described above within the framework of Yoshinkan -style kumite, students do ido tanren (literally, mobile or movement training) on a regular basis. Ido tanren consists of moving across the floor in a zenkutsudachi, performing strikes, blocks, kicks, and combinations thereof. It is an integral part of the training routine at the Yoshinkan Dojo and is practiced with vigor in every training session. Through ido tanren, karateka practice moving in a balanced stance while executing basic techniques. Students not only learn to coordinate the whole body and strike with the tanden, but this training is also instrumental in developing very strong hips and legs. Over time this will result in the karateka having a stable yet mobile stance that is rooted, without which the upper body cannot relax and iryoku will not be realized.

When training in kihon (basic techniques), it is important to make a conscious effort to polish one’s technique by refining ever further the technical details of striking as described above. When doing kumite, however, the contrary holds true: forget the fist and strike with the body! As in any budo, mindful repetition of the correct technique is necessary until the movements of the body are coordinated in a natural and spontaneous manner. When that is achieved, the fist will move itself.

2. Unify mind and body

The second aspect of training to actualize iryoku is to unify mind and body. When the body (a physical manifestation of technique, posture, breathing stance, etc.) and the mind (that part of our being that directs internal energy and controls mental imagery) become one in training, the body’s physical force becomes magnified and intensified. To unify the mind and body means that the mind plays an active role in training. But this is more than just a mental exercise is itself. There exists a psychophysical connection where mental activity is very much a part of the technique, where a budoka coordinates mental imagery with the martial technique during kihon.

Training of the body is comprised of more than simply learning techniques, although this is an essential component of practice. The techniques must be practiced with the aim of perfecting each basic movement, practiced to the point where the movements have been ingrained into the nervous and muscular systems of the body and are a component of the autonomic nervous system. At this point, the body will be relaxed and fluid, with no tension in the movement. This state of relaxation is essential to facilitate the flow of energy within the body which is governed by the mind. This is where mental imagery comes into play. When practicing kihon, the mind will project mental images of cutting, piercing and penetrating over and over until the body becomes able to actually perform such functions. In layman’s terms, it is simply a condition known as mind over matter, where the power of suggestion has an incredible influence on the performance of the body. Kihon is repeated over and over with the mind playing an active role in the technique, so that eventually the body is infused with the energy of the mind to make the potential piercing and cutting capabilities of the body a physical reality. The self, as a function of the mind and body, now has tremendous confidence from this psychophysical union and iryoku manifests itself in every movement that is done with balance and relaxation.

Let’s go back to our previous example of the chudan oizuki of the Yoshinkan Dojo. When a beginner initially learns the specifics of the technique, for example, the placement of the hands, the forward motion of the fist, etc., the mind is occupied with directing the body to move in a certain fashion, a way that is probably new to the student. This process occurs for many years, until the movement becomes more or less second nature and the body has learned to completely relax. The student is then ready to proceed to the next level of training. The mind is still working on perfecting the physical technique of course, since this is a never-ending process, but it now brings a new realm of mental activity to the technique. Punches and kicks as practiced at the Yoshinkan Dojo are penetrating-type techniques; they are not done with a snapping motion of the arm or leg. Students are taught to pierce the target so that the force generated by the fist will penetrate through to the other side. When doing kihon, the mind now takes an active role in visualizing the energy of the body moving through the arm, through the fist, to continue on through the air as far as can be imagined. Students usually punch as if to try and hit the opposite wall, and although this is physically impossible, various mental images are utilized to accomplish this. One way is to imagine that there is a beam of light emitting from the fist at the end of the punch that reaches, for example, the wall facing the karateka. The student mentally attempts to pierce the wall with the fist by projecting mental energy. The student incorporates this exercise into every kihon session. After many years of such training, the punch will take on truly penetrating characteristics, and will pierce a target that is not hard and solid, like the human body for example. The aim of the karateka is to train to the point where the energy will flow from the striking implement, whether it be a fist, knifehand, foot, wooden staff, or the like, without having to be consciously directed by the mind, so that it too, along with the technique, will happen naturally and instinctively. At this point, the physical technique will have fused with the energy of the body to become one, which will elevate the power potential of the karateka to a truly advanced level. The technique just “happens” with energy extended naturally. The same principle applies to shuto (knifehand) techniques, which are cutting in nature, to blocks, which are sweeping and parrying type movements, and to kicks, which are also penetrating techniques.

A critical factor in achieving mind/body unification is for the upper body to maintain a relaxed state even when in motion. This condition is also necessary to attain whole body coordination as discussed previously. The upper body becomes relaxed in two ways:

  1. when a technique has been repeatedly drilled into the body so the movement is fluid and effortless, and
  2. when the hips and legs have become very strong through proper stancework and the tension of the upper body can be effectively “dropped” to the lower body.
Being relaxed does not mean you are a “limp noodle”, but requires attaining a mental and physical state where internal energy will flow and the connectivenesss of the body will channel power through the tanden to the strike or block. When the karateka is relaxed mentally, he/she will remain calm even when outside stressors illicit negative emotions such as fear, anxiety, doubt, and anger, especially during moments of danger. A clear mind that can exhibit good judgement and not be affected by negative emotions during times of high stress will serve the karateka well in all aspects of life.

The above concepts relating to iryoku are to be worked on during practice time in the dojo until they are automatic, natural and spontaneous, in effect hotwired into the whole self (mind and body). Through correct and consistent repetition, the karateka will make the concepts their own and be able to understand with the body.

It is interesting to note that the true extent of one’s power is not always visually evident to others. A strike performed correctly will be deceptively weak-looking and appear to be lacking any force, yet it will actually be very powerful and extremely difficult to block. It is only by being on the receiving end of the technique that one can fully appreciate the actual power being generated.


The basic premise of this article is that power in the martial arts is not limited to mere physical strength, although a minimum of strength is required to perform the techniques. If power was only defined by muscle mass, then the bigger and physically stronger fighter will always triumph in kumite, which we know is not the case. One drawback, however, to iryoku when compared to chikara is time. The training described here is not a “quick fix” method, nor is this article about “How to master karate in 7 days without breaking a sweat”. It may take ten or more years of serious training in the prescribed manner before one even begins to feel the development of true, internal power. It is my belief that for those willing to commit to learning to unify mind and body and to coordinate whole body power, the benefits over time will be immeasurable.

When looking at the full spectrum of budo training, power development is but one small facet of the Way, albeit an important one. The martial prowess of a budoka is determined by other factors as well, such as speed, fighting spirit, knowledge of kyusho (vital areas of the body), breathing, and balance. While all these things deserve consideration, they are beyond the scope of this article about power. The main point is that a budoka should aim to build iryoku to tap the true latent power that exists within the self, and to grow physically and spiritually even as their strength and speed may deteriorate with age in order to reap the full benefits of the Way.