An ornamentaldesign for a running board, as shown and described.
FIG. 1 is a perspective view of the running board according to my new design;
FIG. 2 is a front view of the running board seen in FIG. 1;
FIG. 3 is a rear view of the running board seen in FIG. 1;
FIG. 4 is a left side view of the running board seen in FIG. 1, the right side view being a mirror image thereof;
FIG. 5 is a top view of the running board seen in FIG. 1; and,
FIG. 6 is a bottom view of the running board seen in FIG. 1.
In the drawings, the broken lines depict portions of the running board that form no part of the claimed design. Shade lines having a combination of long and short lines in the figures show contour and not surface ornamentation.