Abstract: Disclosed is a dumbbell to be used during a weight lifting exercise program. The dumbbell includes a handle assembly and a pair of collars connected at opposite sides of the assembly. First and second sets of weight plates are detachably connected to each other and to the pair of collars. Each weight plate has an electric motor carried in a cavity formed therein. The dumbbell is seated in a portable dumbbell tray which includes a touch activated display at which a user can enter a predetermined weight to be lifted by the dumbbell during his exercise. The dumbbell tray also has a processor and a motor controller by which the electric motors of respective weight plates are selectively activated to cause the weight plates to be connected together to correspond with the weight entered by the user at the display.

Abstract: Disclosed is a dumbbell to be used during a weight lifting exercise program. The dumbbell includes a handle assembly and a pair of collars connected at opposite sides of the assembly. First and second sets of weight plates are detachably connected to each other and to the pair of collars. Each weight plate has an electric motor carried in a cavity formed therein. The dumbbell is seated in a portable dumbbell tray which includes a touch activated display at which a user can enter a predetermined weight to be lifted by the dumbbell during his exercise. The dumbbell tray also has a processor and a motor controller by which the electric motors of respective weight plates are selectively activated to cause the weight plates to be connected together to correspond with the weight entered by the user at the display.