By Prof. Dr. Emeric Arus/Founder of the Int’l. Sendo-Ryu Karatedo Federation

Copyrighted by Prof. Emeric Arus

Energy is the capacity for doing work. Energy takes many different forms such as: Solar, mechanical, electrical, chemical, nuclear, heat, and sound energy. Mechanical energy has two different manifestations: 1) Potential energy which is the capacity of a body to do work by virtue of its position relative to a reference, measured in Joule, and 2) Kinetic energy which is the energy due to its motion/action. Kinetic energy also has two forms of manifestation: Linear kinetic energy (LKE) and angular/rotational kinetic energy (RKE).

Both linear and angular kinetic energy are dependent upon the interaction of mass and velocity. If we take the mass and velocity in each case as a constant attribute, the angular kinetic energy is much stronger than the linear kinetic energy. This is because in rotational motion any mass tends also to accelerate due to centrifugal (pseudo) force; and during the time of liberation of the body mass with the technique, e.g. spinning back kick, the energy liberated will be much stronger than in the case of linear kinetic energy. In this case a punch such as an uppercut, a fencing technique such as cut, or a spinning back kick will be much stronger than techniques executed linearly.

An explanation is important here why is a spinning back kick stronger than a straight front kick. During a rotation the body along with the kicking leg holds a grouped position (the kicking leg is closed to the body). Before the liberation of the kick the rotational angle which is approximately 123 degrees measured between the shoulder line and the thigh (see Figure B and C). Later on will be larger approximately 140 degrees (see Figure D). The figure graphically represents the spinning back kick.

Before the impact to the face the degrees between the leg and the thigh will be approximately 160 degrees. Because the kicking leg will be straightened out, the leg will have a longer range for attack (longer lever) and in this case will gain speed. By gaining speed will have also a better penetration power.

These two forms of mechanical energy have important biomechanical implications for the understanding and controlling of the technical executions of the various martial arts.

Let’s start with something of a simple explanation to understand energy. The following will describe different forms of activity (non activity) where the martial artist can conserve his/her energy the best: meditation, sleeping, lying on supine position. Now let’s turn our undivided attention to the practice of martial arts. To understand better which martial art will conserve your energy best (understand the kinetic energy), first we should classify martial arts according to energy expenditure.

In the author’s opinion here are the various martial arts selected in order of energy expenditure, the first denoting the most energy expenditure: Total martial art (including wrestling, kicking, striking etc.), boxing, Judo, Jujutsu, Muai Thai, Karate, Kendo, Fencing, Aikido, Tai Chi Chuan etc. Another classification is between the arts themselves. Karate, for instance has many different “styles”; some styles are recognized as “soft styles,” and others are recognized as “hard styles.”

Hard style karate demands more energy expenditure because almost every action/attack and even defense must be done with the total concentration of the athlete’s energy. The more energy that is invested in an attack the more destructive will be the effect of that impact.

Most of the attacks demand anaerobic power, where the oxygen is insufficient. In order to invest more energy into the action, the athlete loses not only mechanical, but also physiological and mental energy (where the electrical and chemical energy exchanges takes place).

The above figure explains the way of the right kicking leg to the target. Initially the attacker stay with the left foot forward and his/her shoulders are oriented diagonally (see fig. A.). The attacker will turn around to the right and makes almost a 360^o degrees. At the time of the impact his/her shoulders will change position (fig.D.)

Soft style karate uses less energy because the actions/techniques are executed more gently. The athlete is not required to perform anaerobically, and most importantly the athlete uses techniques with soft guiding movement.

Further analyzing the different techniques within a style, we observe that kicking techniques require more energy than punching techniques for two reasons: Legs are heavier than arms; legs must work harder against the force of gravity. Accordingly, the higher an athlete lifts up his/her leg the more energy is needed.

Soft style karate tends to use more body shifting, explaining that it is easier to avoid an attack than to block. There is a big misconception about this proposal. Let me explain this misconception in detail. It is true that when two body parts collide there is a dissipation of energy (explosion of energy), this is the case in hard style karate; but it is also true that when you must avoid an attack by moving away, you also lose energy by moving. Now the question is which action makes you to lose more energy? The contact time (explosion of energy) or the body movement?

The attacker always loses more energy than the defender whether there is contact or not. Theoretically the defender should lose more energy when he/she is moving than simple just blocking and holding his/her position. Moving a larger mass such as the body,

The defender will lose more energy than moving a smaller mass such as an arm. So why do many of the proponents of the soft style promulgate and maintain that body movements/shifting (Tai sabaki in Japanese) will make you to be more economical.

There is one answer to this controversial aspect of “controlling” your opponent and/or “conserving” your energy. These two words controlling and conserving are related to each other, but they have different meanings. Controlling your opponent means that you can direct/redirect his/her actions (attacks, even his/her thought) in your favor. Conserving means maintenance of your previous actions in a smooth way, and by this way your actions will be economical, and you will use less energy conserving it in your favor.

I explained some aspects about conserving the energy in your favor. Now I’d like to add a few words to clarify the aforementioned issue of conserving energy in martial arts. An excellent martial art instructor should guide his/her martial artist’s training combining hard style and soft style techniques. If the training is extremely hard for a very long period of time (months of training) with little or no rest between the training sessions, the martial artist enter in a so said overtraining or burn out state. By using an adequate training protocol the martial artist will be able to control his/her actions and in this way he/she will conserve energy.

This article is simplified for everyone’s understanding. The article did not contains the biomechanical formulas e.g., F = m · a (F = force, m = mass, a = acceleration) etc.

Any comment, please contact the Int’l. Sendo-Ryu Karatedo Federation:

www.sendo-ryu.com kaicho162@yahoo.com drarus@earthlink.net