I have use this 3 time a week since i have buy it , up until recently . it work pretty good , i can really feel it in my arm -lrb- `` good burn '' -rrb- although i havent see much of a change , in the excess `` flab '' on my arm . the only thing be i havent be able to use it for about a week now due to it take a toll on you shoulder . i hurt mine do the behind the head thing . as long as you jus due it in front of you its ok . im glad i end up buy it throw amazon vs. when it be as see on tv .