The ornamental design for a fitnessblock with weightfasteners, as shown and described.
FIG. 1 is a perspective view of a fitness block with weight fasteners, depicting a rectangular shaped weight attached on a right side;
FIG. 2 is a front view of the fitness block with weight fasteners, depicting a rectangular shaped weight attached on a left side and the rectangular shaped weight attached on the right side;
FIG. 3 is a side view of the fitness block with weight fasteners, depicting the rectangular shaped weight attached;
FIG. 4 is a top view and bottom view of the fitness block with weight fasteners;
FIG. 5 is a side view of the fitness block with weight fasteners, depicting a small circular shaped weight attached; and,
FIG. 6 is a side view of the fitness block with weight fasteners, depicting a large circular shaped weight attached.
In the drawings, the dash-dot-dot-dash line showing a weight depicts environment, and forms no part of the claim.