this be now week six for I . I can not believe my eye . I use it everyday . I can only do one minute behind my head for my triceps because it burn so much . I have increase from one minute to three minute in front for my biceps . I try this because $ 15 be nothing after ready that many people love it . I think if you be a gym rat , this be not for you , however , many woman have really poor arm strength and this be a wonderful start . my arm be tone and the fat be disappear . I have lose one inch on each arm because I measure it before I start use it . once this become too easy , I plan on buy the man 's Shake Weight .