implementations of the present invention relate to devices , systems , and methods for the safe and efficient use of exercise equipment and , in particular , weight training equipment . a locking hub for weight training equipment may include a first hub and second hub , the first hub and second hub having a sleeve located therebetween . the first hub and / or second hub may hold one or more pads adjacent the sleeve . rotation of the sleeve relative to the first hub and / or the second hub may compress the one or more pads to force the pads radially inward against a weight bar , substantially restricting movement of the locking hub relative to the weight bar .