I do not have space for a lot of exercise equipment but I be interested in strength training and lifting weight . my brother have a shake weight and love it so I decide to get one too . after give it a chance , I have come to the conclusion it be just not for I . I can not seem to get it to work as seemlessly as they do on the dvd workout . plus it be only two and a half pound so it do not do much when I be use to use five pound weight . I suppose it be responsible for somewhat tone my arm but I prefer regular weight . it be a nice idea in theory , but hard to use in real life .