For your consideration: 4 phases of a still-shape practice.
Phase 1: the shape matters.
> You use some amount of will to get into a particular shape and stay there.
(Language: muscle, fascia.)
Phase 2: the route you take to get into the shape matters.
> Each asana begins the moment you begin moving in its direction. There are 10,000 ways to get into forward fold, and each will yield a different forward fold.
Phase 3: the options you have along the way, and the options you have within the shape itself, matter.
> You have options, can move this way or that along the way to, and once in, a shape, adapting to a moment-by-moment reality changing in front of and within you.
(Language: nervous system.)
Phase 4: who you are, and the way you are being that, matters.
You’re aware that you are not just a person on a mat making a shape and breathing some way. You affect and are affected by any and everything else.
(Language: heart / electrical (this one I’m least sure of, but there's some really wonderful evidence describing the body’s electromagnetic field, of which the heart is a kind of centerpiece, creating and receiving these impulses)).