I try the shake weight , know full well that I would have to do the shake . many of the negative review of this product seem to think that the weight itself should be shake , and that be the sole reason why they do not like it . overall , I think this product be pretty good . it be very difficult to learn how to use , in order to keep it shake while move it around , and I think you have to make sure that you reverse you grip from time to time in order to get even work on both arm -lrb- if you hold it with you left hand on the bottom and the right hand on top , you be probably not work both evenly -rrb- . the dvd , nor the product manual seem to indicate this , but I find that it be easy to figure that out by try it . if you be not go to take the time to work with this , just like any product , you will not succeed . you probably will not even figure out how to do it right , the shake of the weight while try to keep you muscle mostly stationary as they say you should do be actually very difficult . it will take practice , but for upper body exercise at home , I think this be a pretty good solution for home strength training . I would have like to see a wider range of weight , or at least a notch or something to add a extra one pound weight or something . as it be , once you use this often enough , you 'll outgrow they `` 6 minute workout '' and start need something else .