When you say you're doing it over and over, what are you redoing? First, I think you might be focusing too much on drawing what you see, rather than making up the rhythm that you feel runs through the figure.Cuz I see nice contours, which shows you can reflect what you see in your drawing, but for these exercises, it's not so much drawing what you saying as 'finding' the rhythm/flow that YOU think represents the figure's movement (and that involves the creative processes of interpretation, exaggeration, and simplification of what you see).The lines are sketchy, which could reflect that you're not confident or feel rushed by the time limit, but spend a few seconds thinking of what line you think runs through the figure before actually marking the paper (and if that means adding 15 more seconds so you can do so comfortably, do so). This might help: first, you can picture, in your head, the line you want on the paper without actually marking the paper. Then, when you see the line clearly, draw it slowly so that you're in control of the pencil the entire time. It might help to "ghost" draw a line a few times--aka, draw your line without putting your pencil to the paper--a few times before actually marking the line. tldr, plan the line you want to draw, "ghost" the line you want to draw, then draw it.
