The ornamental design for a fitness weightset, as shown and described.
FIG. 1 is a perspective view of a fitness weight set showing the design of the invention.
FIG. 2 is a front view thereof.
FIG. 3 is a back view thereof.
FIG. 4 is an end view thereof, the opposite end being a mirror image; and,
FIG. 5 is a top view thereof, the bottom being a mirror image.
The broken lines in the drawings showing the fitness weight set in FIG. 1 are directed to environmental subject matter only and forms no part of the claim. The fitness weight set is shown with symbolic breaks bound by brackets in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.