Even though you train to be stronger, faster, more flexible, or just plain tougher, self-defense techniques, or a self-defense system, should require little of this to work. You should put the effort into developing your strength and speed and flexibility when you are young; otherwise, you won't have much of anything when you are older it is sometimes said, but the techniques themselves shouldn't depend on strength or speed to work. In the first place, there will always be someone bigger or stronger or faster. But more importantly, your self-defense should work for you when you are old, when you may be least able to defend yourself.
|Twisting the head in|
|Knee attack to the head|
in Saifa kata.
to head in Seisan.
Whatever the case, it should be effortless. And it is usually effortless because we have moved in such a way that the opponent is not given a second opportunity to attack, our first block/attack is often simultaneous, and we bridge the distance to attack the head or neck.
Relax, relax, relax...you'll be faster and stronger.