it seem from what I have read so far , for many people this product produce some sort of positive result and I will not dispute that . but for the other who write the bad review they word should not be take so lightly or even callously berate . the tv ad be misleading . I do not think anyone expect the weight to shake on its own , `` do the workout for you '' as many critical commenter have claim . but the tv commercial give the illusion that a initial shake must be initiate by the user and some sort of centrifigul method would take over and it would be the responsibility of user to tensely hold the weight use the require muscle need to stabilize it only to find you can not stabilize it , thus cause rapid muscle growth . well it just do not work that way . you have to constantly shake the weight yourself , and I find that a very couterproductive way to permanently build muscle . even in the best of the review nobody really rave about this product so I can not see the logic as to why they rate this 5 or even 4 star . go figure . update 1\/21\/2012 . alright I see this sit on the shelf at Walgreen 's a long time ago and I ignore it . then I go to CVS . on the same day ! again I see one lone Shake Weight for Men sit knee high on the shelf . I walk away . but the thought pursue I . be this fate ? should I buy it or not ? will the person at the register laugh at I ? will it offer some sort of benefit ? so I cave in and buy it . when I get home and open it inside there be a dvd on how to use this thing properly . the goal be to shake the weight vigorously steadily and firmly without wobble it for 30 seconds per exercise . the best I can get be 22 seconds . when you use the Shake Weight properly it will make a whooshing noise . if you hear a kadunk kadunk kadunk you be do it wrong ! as for the benefit themselves , that be just simply go to depend on you own current physical condition . for I I find the Shake Weight to be great for warm up before real exercise or for add a quick firm-up AFTER real exercise .