This really needed some speed indicated through blur or some sand kicked up to communicate your idea fully. The selection is a useful touch, DOF could have been a touch longer and contrast stronger. Nicely composed otherwise.
Good thinking, It would have been better to see all of the left foot's heel in the frame and it's to much blurred uninteresting foreground, cut some of it off and you'll have a better photo IMO.
Not sure you you did it, but the photo has a lot of movement... I like the way my eye moves from bottom left to top right. The little piece of color is an interesting addition... my favorite of the challenge.
Good shot, it is interesting, and has a story ... I am assuming that the person is running towards the life saver thing because someone is in the water?? However, it looks a little like the person could be just standing and raising a leg instead of running though, because I can't see much movement in the picture. When you run there is usually sand flying around near your feet. Goodluck.