Karate's finishing focus: a split second of full-body tension exactly at impact, with a sharp exhale — and an instant release right after. Without the release it is just stiffness.
Kime — literally “decision” — is the moment that turns speed into effect. The speed itself is built beforehand, in the kinetic chain from the ground up: in a kick the thigh peaks at around 4 m/s, the shin at 7 and the foot last at almost 12 m/s, in sequence rather than together. Kime funnels all of it into one point. Two errors cost you that: holding your breath or inhaling at impact, which drains stability exactly where you need it, and holding tension throughout the whole technique, which makes you slow and tired. What you want is a sharp exhale, a split second of full tension, then instant release. What gets missed: kime cannot rescue a technique whose chain started at the arm. Hips first, then the arm — and rotating the fist just before impact adds 6.7 to 12.2% more impact force on its own.