Look at the tutorials for the Action Camera Center. You can do almost everything in there, including the freeze frame, then take a snapshot of the freeze frame before you do anything else.
Next, use the Fix/Enhance settings to turn down the color of the FF'd section of the clip so it's B&W. Finally place and trim the snapshot image so that's aligned on the track below, and apply an oval mask with some light edge feathering/vignetting to highlight the athlete in full color, but only for the freeze frame.