In my IS type research, it requires lots of focussed time exploring and increasing awareness of what really is going on within my body - which muscles are moving what, and how are they doing so. How can I achieve more with less effort. It is a total retraining exercise. It can be minutely detailed. OFten it is the mental ability to stay with it that is harder than the physical effort (but not always!). The more time I spend on it, the better I get.
Just to play the Devil's advocate...
Why do you think that this can't be or isn't done with any type of movement? For instance a snatch or a clean?
Isn't this exactly what building skill is about?