when the commercial for this item start pop up I start do some research on the Shake Weight . Amazon and other site give it high mark , but the clincher for I be when I start talk to three member of the Central Michigan University Football team . -lrb- one of they be actually go into the NFL draft after graduation -rrb- they be stay at the same hotel we be , and be use it in the fitness room . to a man , all three of they swear that it work and do a great job . I do a few exercise with it and then order my own the next day . I have be use it for a week now , twice a day , and I can tell you that it do work ! I notice a tightness and slight tremble in my arm for some time after the very first work out , similar to the feeling of lift weight for 45 minute or so . I be on the north side of 50 and I have be work out in one form or another my entire adult life . I have also try most of the out-of-the-box portable exercise device - band , isometric , Bullworkers , as well as push up , pull up , etc. . I can say that the Shake Weight be by far the best portable exercise device I have ever use . I be definately sell on this product . there have be some comment that it do not work . if you can not feel result right away you be probably do the exercise improperly . five star plus ...