Abstract: Flexible cables extend upward from a carriage slidable along an upright column, then over guide pulleys and downward to a barbell. Latch mechanism interconnects the carriage with the column so as to support the weight of the barbell. The latch mechanism is releasable by actuation of an electromagnet to permit normal exercise by raising and lowering the barbell which causes corresponding lowering and raising of the carriage along the column.

Abstract: Externally threaded opposite end portions of the bar of a barbell are insertable into the central apertures of cylindrical weights. Locking sleeves having manually retractable inward-projecting locking pins are fittable on the externally threaded bar end portions. With a locking pin in its projected position, the locking sleeve can be rotated like a conventional nut so as to advance toward or away from the weights. With the locking pin held in a retracted position, the locking sleeve can slide longitudinally in either direction along the threaded bar end portion without rotating.