You have a good understanding of light and shadow. I feel you need more figure drawing practice IF you were going for realism. The abs are off. I get they are running, and that abs in generally are not usually perfectly symmetrical in real life but I cant help but feel they should be of an even width. Maybe the left side is smaller because the muscles are contracting to bring that leg up? The shading on the back leg's knee makes the leg look like there is a dent just under the knee. Another good rule of thumb is that a foot will always point in the same direction as the leg's knee. Sure you can move it around a bit but the back foots position seems unrealistic to me. I see a crazy amount of potential, and you WILL reach it with continued practice. Do not let this review discourage you please. That is NOT the purpose of it. You will be one of the greats if you stay dedicated to your studies. I hope to see your works in the future to see how they evolve.