Some people "cycle" their steroid doses. This means they take multiple doses of steroids over a period of time, stop for a period, then start up again. "Stacking" means taking two or more different anabolic steroids. Other steroid users may "pyramid" their steroids, starting with a low dose and gradually increasing the dose, frequency, or number of anabolic steroids taken, then tapering off to complete a cycle. Users believe that stacking enhances the effects of each individual drug, pyramiding allows the body to get used to high doses of steroids, and steroid-free periods help the body recuperate from the drugs. There is no scientific evidence to support any of these claims.