The ornamental design for a runningband, as shown and described.
FIG. 1 is a perspective view of the running band showing a new design;
FIG. 2 shows a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a side view thereof
FIG. 5 is another side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
In the above drawings, the broken lines form no part of the claimed design. The surfaces of the running band between the top perimeter opening edge defined by a solid line and the bottom perimeter edge opening defined by a solid line define portions of the running band that form no part of the claimed design.