Abstract: Apparatus for securing weighted plates to a barbell or dumbbell, and a method of use thereof. A mounting subassembly includes an actuator for expanding and retracting the mounting subassembly, and a mount for securing the mounting subassembly to an edge of a sleeve or handlebar of the barbell or dumbbell. A locking subassembly is disposed about the mounting subassembly in a collapsed state. Weighted plates may be placed over the mounting subassembly and locking subassembly on the barbell or dumbbell sleeve when both are in their retracted and collapsed states, respectively. The locking subassembly is expandable to a diameter larger than the barbell or dumbbell sleeve via engagement of the actuator to expand the mounting subassembly. The locking subassembly may then slide up the sleeve, and rest against the weighted plates to secure them in place on the barbell or dumbbell.