The Australian reports that extended stints in front of the computer can cause blood clots to form such as those that occur from Deep Vein Thrombosis. Researchers have named it e-thrombosis (what is it with naming everything to do with computers e something?). So just get up out of your chair, slowly so not to make your body go into shock, and walk to the other side of the room and back. Now do that every hour and you should be right according to this article!