FIG. 1 is an isometric view of an ornamental design for a center interface adjustable weight fitness training device;
FIG. 2 is an exploded view thereof;
FIG. 3 is a front elevation view thereof, the rear elevation view being a mirror image thereof;
FIG. 4 is a sectional view thereof, taken along a sectional line AA shown in FIG. 3;
FIG. 5 is a top plan view thereof;
FIG. 6 is a sectional view thereof, taken along a sectional line BB shown in FIG. 5;
FIG. 7 is a sectional view thereof, taken along a sectional line CC shown in FIG. 5;
FIG. 8 is a top perspective view thereof;
FIG. 9 is a bottom perspective view thereof;
FIG. 10 is a right side elevation view thereof, the left side elevation view being a mirror image thereof;
FIG. 11 is a top perspective view thereof, showing an additional cylindrical weight added to the center interface adjustable weight fitness training device;
FIG. 12 is a top perspective view of the center interface adjustable weight fitness training device with connection ports, showing a straight bar inserted through the connection ports;
FIG. 13 is a side elevation view thereof in an inverted position, showing connection of a resistance chain through a connection port;
FIG. 14 is a side elevation view thereof in an inverted position, showing connection of a resistance band through a connection port;
FIG. 15 is a perspective view showing the center interface adjustable weight fitness training device positioned on a foot of a user; and,
FIG. 16 is a perspective view showing the center interface adjustable weight fitness training device held in each hand of a user.
The broken line showing of the internal non-visible structure in FIG. 7, additional cylindrical weight in FIG. 11, the straight bar in FIG. 12, the resistance chain in FIG. 13, the resistance band in FIG. 14, the foot of a user in FIG. 15, and the user in FIG. 16 illustrates subject matter that forms no part of the claimed design.