I decide to buy this product at target after read the positive review and I have to say , this thing work . I use to go to the gym and lift weight and tired of the routine . after a few year of work out at home only once in a while , my body have become soft and I want something to help I get back into shape without take up a lot of space in my house and something that be convenient but also target a lot of muscle in my arm and shoulder . so this product be perfect ... so ... let talk about my first two day ... I can not fully complete the full 6 minute work out and my muscle be burn . I would end up have to do it for 15 sec on each set out of 30 seconds . so it do work ; even thou a lot of people like to make fun of the way it look when you work out with it . also , I see some video of people work out with it and do it wrong and say it do not work . they posture be wrong , they do not keep they body still , and when they be do a set , they would only do it for 5 seconds and switch it to another arm . if they try to do the 6 minute workout , they would of be to embarrassed to post the video online . I think this product be perfect for people who work full time , do not have time for a 30-60 min of weight lift a day and who sit at a computer all day . I be one of those people and I see it as ... at least I be do something . I have read after a while of use this device , people start to do it 2-3 time a day . I plan on get there ... but I be also plan on add 3 set of push up towards the end use the Perfect Push up device and also do some dip since I be not feel my chest burning use the shake weight .