A Chinese doctor “ka-jya” in a Chinese post-Kan era wrote a book called “Gokin no gi,” which described animal behaviors from the ecological science point of view. According to this book, breathing is one of the techniques which all animals posses instinctively. By the combination of timing of exhaling and inhaling, they become relaxed. Breathing changes as a reaction to their body movements in various situations. “Kikou-jutsu” is said to be a good use of this breathing technique. It teaches that by exerting the ultimate concentration and releasing Ki (spirit) a competitor would not only be able to control one’s own actions but also the action of the opponents. “Kikou” literally means “the spirits of oneself”- by freely controlling one’s latent energies, these spirits directly address one’s body and the spirit and in turn affect the spirit of the opponents. A basic principle of Kikou trainings, to the best of my knowledge, would be a breathing technique with which one’s spine straight up. To take energy from the natural world into one’s body by inhaling slowly and then make it explode by exhaling it all at once. This is what we called utilizing the stored energies of the powers and the spirits.

The act of breathing is physical as well as biologically important factors for athletic aspects of one’s health. It requires a very intensive concentration and heavy demands on the body far greater than one could imagine. In ordinary life, one would maintain the balance of the time of breathing and movements unconsciously, however, judging by discomfort one feels in the diaphragm, especially after being sick or having a cold, one easily realize that the act of breathing demands so much more from one’s consciousness than simply inhaling and exhaling. The less active other parts of the body become, the more instinctive breathing becomes. This is one reason why one can not do hard exercises and maintain a natural breathing pattern, as it especially inhibits the reflexes and the ability to move accordingly. Therefore, not to mention in kumite fighting, it is very important for one to not let the opponents to sense one’s breathing level, so as not to give any advantage for the opponents to gain a superior position.

An important point of the physics aspect of breathing is the contraction of one’s muscle. That is, the body becomes hard by controlling the timing of ones’ breathing.
An example would be the avoidance of serious damage from an attack by making one’s muscles tense. This allows all of one’s energies to come together in the large areas of one’s body. By temporarily increasing the peculiar vibrations on the body muscles, by doing so, the body is able to absorb the pain from the damage to one’s body and block the nervous system’s reaction to damage. One can imagine this by considering the difference it would be between one flicking Tofu with a finger and flicking of Konnyaku jelly (devil’s-tongue). It is certainly very important to develop the strength needed for receiving the blows as well as the techniques of attack. The moment to deliver stored energies of the powers and spirits to the opponents, as I mentioned it before, would be displayed by the tightening of muscles so one could make good use of the stored energies for attacking instead of concentrating on the pain of received blows.

Let us explain it in detail. F (Force) = m (mass) a (acceleration). As you can see, this is Newton’s theory (the second rule). In order to increase the power to deliver effective movement to the opponent, that is F (Force), one would either need to gain m (mass), or a (acceleration), or both. In present kumite competitions, it is debated as to whether this theory is important or not, I would rather leave it to other opportunities to discuss, nevertheless, it is needless to say that one’s daily trainings are all about this equation.
For karate-do attacking, the forces that counteract F (force) would be friction-resistance and air-resistance. Consider the front of the fist area, one could ignore the later, however the former, friction-resistance would be increased when one’s body is unnecessary tensed. Therefore, one does not need excessive strength in the whole body’s movements, rather just enough strength to hold one’s body steady while the fist is in motion.

Let us discuss Oi-tsuki (stepping forward and reversed punch) and think about mechanics of this motion. Take the power that is produced by the instant moment when one’s body steps out from being relaxed kamae(basic guard); the moment a foot is landed without being interrupted by the law of inertia, making one’s joins locked from an appropriate angle towards the toe, ankle, knee and finally back. Add the energies that are produced by the Hikite (a pull-back arm) action as well. The sum of the energy that is generated by these coordinated movements of the body are then concentrated into the fist and delivered to the opponent. Even the velocity of the foot being landed would make good use of its reactionary power.
Energies exerted by the movements, such as circles or straight lines, on the various kinds of bodies parts are controlled by the lengths of time that it takes to complete the motion and the amount of contract with the joints; energies expended are increased by m(mass) by focusing on the final target; increasing a(acceleration) when being relaxed; and finally F(force) is increased as a result of the total action. For putting these into practice, ones must have, not to mention, enough stamina to endured a rigorous training, perfected focus technique to foresee the target’s movements, and above all, it is essential that one must achieve and maintain the spirit, which is superior to the opponent’s.