Over sharpened feel of the image does not to it any favors. The blank background is not a good choice. A clever use of slight violet shade on the arm with the blue hand weight, but the hand fades into the background and the arm does not have a lot of definition. A good effort and concept just a little lacking in execution.
I like the photo other than the purple tinged arm. To me a purple or blue skin tone would mean death or sickness, not fitness. Not sure why you went with selective desaturation when a natural looking skin could would have been fine.
Nice selective desat, though I think for stock photography it might be nice to have it in color. Not that I know much about it. Great lighting, very even and soft.