The ornamental design for a gymtowel, as shown and described.
FIG. 1 is a front view of the invented towel.
FIG. 2 is a back view of the embodiment shown in FIG. 1.
FIG. 3 is a right side view of the embodiment shown in FIG. 1.
FIG. 4 is a left side view of the embodiment shown in FIG. 1.
FIG. 5 is a top view of the embodiment shown in FIG. 1.
FIG. 6 is a bottom view of the embodiment shown in FIG. 1.
FIG. 7 is a perspective back view of the embodiment of FIG. 1; and,
FIG. 8 is a view of the embodiment of FIG. 1 showing appearance in one mode of use on a weight bench. The weight bench shown in dashed lines is not claimed.