Kime is one of the central concepts of karate and, most likely, the most poorly translated.
What the Word Actually Means
Kime (決め) derives from the verb kimeru — to decide, to determine, to settle definitively. The same verb appears in everyday Japanese: you kimeru a meeting, you kimeru a price. There is nothing esoteric about it.
In the West, kime is almost always rendered as “focus.” The translation is not wrong; it is insufficient, and it loses precisely what matters. Focus is the state preceding the technique. Kime is the moment the technique becomes irreversible: the point past which you can no longer withdraw, no longer correct, no longer hesitate.
This is why kime cannot be trained separately, as a quality. What is trained is the decision.
What Happens Physically
Kime is a brief sequence in three stages, and the order matters more than the force:
1. Relaxation until close to impact. Counterintuitive but decisive. Muscle contracted in advance acts as a brake: the antagonists slow the movement. Maximum limb velocity is achieved through relaxation along the path. A beginner tenses the arm from the outset and strikes slowly, at great cost — which is why his techniques exhaust him rather than his opponent.
2. Sudden simultaneous contraction at impact. In that instant the body becomes a single structure: joints lock, the trunk stiffens, the supporting foot anchors into the floor. The biomechanical effect is called effective mass — the quantity of body mass coupled to the striking segment. A punch thrown with the arm alone transfers the mass of the arm. A punch with kime transfers a significantly larger fraction of the body’s mass. Same velocity, different result.
3. Immediate relaxation. The contraction must last tenths of a second. Held, it turns the strike into a push and blocks the next technique. Zanshin (残心, “the remaining mind”) takes over from here: not muscular tension, but attention that does not withdraw.
Breath and Trunk
The short, controlled exhalation at impact is not ornament. It raises intra-abdominal pressure, and intra-abdominal pressure stiffens the trunk — a mechanism documented in spinal biomechanics quite independently of martial arts. A rigid trunk transmits force from the ground into the arm; a soft trunk dissipates it.
A point of terminology is due here, since two things are frequently conflated:
- Kiai (気合) — literally “the meeting of spirit.” The shout that concentrates intent at the moment of technique. Present across all styles.
- Ibuki (息吹) — a distinct method of forced breathing under dynamic tension, specific to Gōjū-ryū and Kyokushin, paired with its soft counterpart nogare. It is not a synonym for kiai and does not belong to standard Shotokan terminology.
On Ki
Kime is often described as “focusing ki energy.” It is worth saying plainly what we know and what we do not.
Ki (気) is a concept from East Asian cosmology with no counterpart in modern physiology — it has not been measured and cannot be measured with current instruments. What can be measured is neuromuscular coordination, kinetic chain sequencing and momentum transfer.
This does not render the concept useless. The vocabulary of ki describes real sensations experienced by the practitioner, and it remains the best teaching instrument we have: “send the energy through the fist” produces a motor correction in a student that “sequence the kinetic chain proximal to distal” does not. But it is an instructional metaphor, not a physical description — and a mature practitioner is entitled to know the difference.
Kime and Mushin
The link between kime and Zen runs through mushin (無心), “the mind without thought” — or, more precisely, the mind that does not stop anywhere.
The classical source is not karate but predates it: Fudōchi Shinmyōroku (“The Unfettered Mind”), written in the seventeenth century by the Zen monk Takuan Sōhō and addressed to the swordsman Yagyū Munenori. Takuan’s thesis: a mind that fixes on any one thing — the opponent’s sword, one’s own technique, the fear of losing — is a stopped mind, and a stopped mind is late.
Applied to kime: the decision cannot be taken by a mind that deliberates. It must already have been taken by the time the body executes it. This is why kime is trained through repetition rather than through understanding — repetition moves the decision from somewhere it is thought to somewhere it is merely done.
What the Research Says, and What It Doesn’t
One thing worth stating, even though it does not flatter my subject.
It is frequently claimed that karate training increases bone density. The available study on this question (Ito et al., Revista Paulista de Pediatria, 2016), which used DXA to measure bone mineral density in 138 adolescents, found higher values among judo and kung-fu practitioners — but among karateka, values similar to the control group. The authors’ explanation: the style studied was Shotokan, semi-contact, in which actual impact is rare in training.
The honest conclusion: karate has a great deal to offer — coordination, balance, strength, control of attention. Bone density does not, on current data, appear among them. A style that does not need false arguments should not use them.
Kime Outside the Dojo
Applied to life, kime does not mean “concentrate better.” It means something else, less comfortable: the capacity to make a decision and to close it.
Most people do not suffer from a lack of focus. They suffer from decisions left open — half-made resolutions, returned to, re-debated, consuming attention for months without ever converting into action.
Kime is the exact opposite. It is the moment in which you have decided, executed, and withdrawn from the decision. And then, as in technique: immediate relaxation, and attention to what comes next.
It is not by accident the hardest thing to learn in karate. Or outside it.