A pace-adjusting mechanism of an elliptical cross trainer having a U-shaped
coupling rod pivotally and laterally disposed on a bottom support frame. An electric adjusting mechanism is interposed between the U-shaped
coupling rod and the frame unit. The electric adjusting mechanism includes a motor, a guide spindle sleeve and a telescopic spindle. When the telescopic spindle is driven to be moved, it results in the adjustment of the relative angle of the U-shaped
coupling rod, and wherein an L-shaped connecting rod is pivotally coupled to each top side of the U-shaped coupling rod while the end of the L-shaped connecting rod is pivotally attached to a
treadle plank so that the vertical position of the
treadle planks is adjustable by changing the angle of the U-shaped coupling rod and, therefore, the adjustment of the exercise pace is achieved.