The shot doesn't work for me. The sky has a lot of noise and seems oversaturated and your subject, I believe, would have been better suited facing the camera.
The author chose a difficult angle which is a plus, but the image doesn't particularly convey any sense of fitness. Certainly a good effort - it just doesn't seem to have a purpose.
I don't think this image has anything to do with the challenge. I am not voting on this image but if I did I would more than likely give it a 4 or lower. Reason being, I don't think you met the challenge's request to take an image of a stock photo of fitness. Other than that the angle tilt is too much, the image is very choppy, and this isn't staged at all.