Here are some quick one minute sketches to represent energy. I suppose the emphasis here is to try to capture the gestural line of the body. A minute is not long enough for details but I like the line of the body in all three images here.
Two more one minute sketches:
The first one seems a little elongated but I think it gives a sense of movement. The second one I like, even though the arm over the head looks a bit odd, the model had put a sheet over her head so the pose was a little odd but I like the shape of the body leaning over.
Two minute sketches:
Again, there are a few proportion issues but I like the energy here in both figures, the seated twist works quite well as does the leaning pose.
I decided to work on more abstract drawings and here are a selection:
I really like some of these, reducing the body to just a few lines can work well in some cases.