Abstract: The means for securing weight plates (16) on weight rods (10?, 12) or holder bars provides at least one groove (14) formed in an end region (10?) of a weight rod (10?, 12) or in the holder bar. The weight plates (16) are formed with a radial protrusion (17) in their central bore, preferably extending over only a portion of the circumference. The diameter of the bore at the protrusion (17) is greater than the diameter of the end region (10?) of the weight rod (10?, 12) or holder bar axially next to the groove (14). The protrusion (17) falls into the groove (14) and prevents the weight plate (16) from slipping off the weight rod (10?, 12) or holder bar.

Abstract: The means for securing weight plates (16) on weight rods (10?, 12) or holder bars provides at least one groove (14) formed in an end region (10?) of a weight rod (10?, 12) or in the holder bar. The weight plates (16) are formed with a radial protrusion (17) in their central bore, preferably extending over only a portion of the circumference. The diameter of the bore at the protrusion (17) is greater than the diameter of the end region (10?) of the weight rod (10?, 12) or holder bar axially next to the groove (14). The protrusion (17) falls into the groove (14) and prevents the weight plate (16) from slipping off the weight rod (10?, 12) or holder bar.

Abstract: An elongated lever arm has one of its end portions pivotally connected to an upright of a box frame and extends generally horizontally inward into the frame opening. A cable guided by one or more pulleys or rollers is connected to the other end portion of the lever arm and is pulled manually by a user to swing the lever arm. A force-applying or resistance element is connected between the base of the frame and any one of several points along the length of the lever arm between its pivot and the cable. The point of connection of the resistance element to the lever arm can be changed to adjust its effective force resisting swinging of the lever arm. A mechanical stop mechanism is provided to maintain the lever arm horizontal and to counteract the force of the resistance element so that the force adjustment can be made quickly and easily.