I have see some people laugh at the shake weight and make it out to be junk or something that they would not want to be catch or see use . truth be it be a extreme work out . I do cardio and then a total gym machine and then the shake weight for 6 min . just follow the dvd and do it before you laugh . the first time you do it it seem like `` alright '' , . . I can feel it I can do it . but then as the day go by and you stick with it , it will surprise you . it work muscle in area that be hard to normally work . I see my Chiropractor now less and I can feel how my neck and under arm be get stronger . I be 48 and it be very good for some of we older guy once we start to soften up . I have no doubt that young guy will feel a core fitness heat that will surprise you all the same . if you want to get pump up like the guy in the tv add then you will need to do much more of course . this alone will certainly not do it . but with a good diet and some cardio I notice a major upper body work out that be well worth it be price . just make sure you breath when you do it . it be exhausting and it burn but it be the kind of burn that build . the program consist of 30 second evolution with a 15 second recovery strech for each exercise . it will get you attention fast ! I use mine about every day . I have no regret in buy it . for it be intended purpose it be make very well .