I try out and review almost any new fitness equipment I can get my hand on ... it be my `` thing '' . and while we all love fun thing that change we body -lrb- the perfect combo -rrb- , I personally do not feel this be one of they . and neither do the independent professional study try they out . in study compare these to a few rep with good weight , these always lose in comparison . they do not do anything more than handweight , but most study show they do far less . the weight be not enough for the change they promise and you be not actually able to utilize as many muscle as you can with regular weight because you can use those to do far more move than can be do with those need to be do with shake . a good cheap pair of handweight and a good upper body dvd in other word will take the novice or the pro in a far more beneficial direction , therefore , than these will . my own opinion ? I agree . for I the limited way these can be use leave the novelty of they wear thin quickly and the gain from they as equally limit . if you have flabby `` batwing '' under you arm which be often the reason most woman turn to try out arm weight , these will not help like regular cheap handweight will . the move need to conquer those can not be do with a shake weight to any degree of efficiency . instead , you need to crisscross two of you handweight while basically clasp you hand together , or use a kettlebell , keep you elbow next to you head\/above you ear and lower you weight behind you head , slowly raise they , keep you elbow in the same place at you head , and lower again for several reps. you need double the weight you would normally lift with one handweight . the shakeweight primarily target the bicep ... again not as well as handweight rep , but it do ... so , it actually be a better product for man unless a woman just need to specifically bulk up there , I guess if she lift heavy box as a UPS driver or something . : - -rrb- that say , no product be bad if it make someone sedentary work out . in fact , it be good . it be not that I be say these will not do anything -- because they will . and as a alternative to do nothing , they would be a five star review . as woman , we begin to seriously lose muscle every year we age ... it be imperative we do something . be these , to I , a fad that can not do nearly the work of a old school handweight ? absolutely ... and there be dvd upon dvd to show you how to use those . for beginner , the biggest loser dvd would be a perfect example . and with those , if you have no muscle , you can start with a 1.5 lb weight in each hand and just increase as you grow muscle . with these , you do not have the option to cheaply expand with test weight increment . with handweight , you can get they anywhere cheaply as well ... but most importantly with those you can work you entire upper body ... include lift you chest muscle -lrb- this work they slightly , but not anywhere close to what you need for and with the move you need for true chest muscle work -rrb- so you do not only grow biceps , you also get a free `` lift '' and prettier shoulder , and no batwing ! but , if it make anyone sedentary work out ... I say go for it ... you can always progress to handweight or a kettlebell later once you be comfortable ! as a side note , this be just a weight you shake . you can use a bottle of water or can of thing to get start . that be a common tool for personal trainer use what people have around the house . but shoot , you can get handweight for 1\/3 of the price of this . why not get 300 % more result with what the pro use because it be work for decade ? and you get two of those for that price !