how hard be it to produce a work dumbell ? it be not rocket science , it be a dumbell . yet somehow the brainiac at Fitness IQ manage to botch it . they get half of it right - the weight be fine , the center pole be not . when you pick it up , it go limp . you lift it into a curl , and it be jiggle in you hand like a rubber dick . the first time I try it I throw it down in disgust and it flop across the floor like a sick guppy . I would rather go back to lift my kid than use the shakeweight again but my wife take they so I guess I 'll just find some heavy rock in the meantime .