I purchase the man 's shakeweight rather than the one target for my gender because I have always though the weight that be gear towards woman be far too light , for I at least . 6 minute do the various position with this thing make my arm , shoulder , pec , and lat feel like bowl of Jello . I love it . it be so intense , as stupid as it sound . I have be use it nightly for about a week -lrb- 6 minute , 10 minute break , then 6 more minute -rrb- and have already notice a slight change in my upper body . for those who though this thing have battery and move by itself , I really hope you be not in any sort of position of power or managerial occupation . or parent . anyway ... this be one piece of make for tv hilarity that actually work like they say it do .