Strength training (or any training) is, in a way, like mending clothes.
Or mending Taekwondo Doboks, in today’s instance.
Things become stronger where they are repaired.
Our bodies (and thus also minds!) work the same. If there is a pressure/demand put upon it, we adapt.
When we lift a weight, we become stronger. When we jump, our jumping improves.
By moving more, and differently than we are used to, our movement skills refine.
The more we do, the more we learn.
The doing comes first.