As a data base administrator in my 50's I work all day every day at my computer. About 6 months ago I rearranged my desk with shoe boxes under my keyboard and computer to work standing up which I do for 90% of my workday. I can tell you everything seems better. Yes I get tired - especially when away from work for a vacation it takes a while to get used to it again. But I can tell you I now have no stiffness when I leave my desk to go to the ladies room or lunch - how could I? I have been standing all day! I feel more alert and engerized and my legs seem to be getting into better shape and stronger. If I get tired I remove the boxes for a while and sit down. Not elegant but a cheap way to try things out - also got an extreme standing mat for my feet.