[科学60秒] 兴奋剂的持续效果长达数年
参考文本：
Athletes have obviously been tempted to use performance enhancing anabolic steroids. Drug testing may discourage such use. But a new study finds that some of the performance benefits of steroid use may persist years after an athlete stops doping. That’s according to research presented this week at a conference of the American Physiological Society.
Swedish scientists looked at power lifters, a pure strength sport. Steroids can increase muscle fiber size and the number of cell nuclei in the fiber. The researchers found that even years after steroid withdrawal—and with little or no current strength training—muscle fiber density and increased number of cell nuclei were comparable to drug-free athletes currently doing high-intensity strength-training. The additional cell nuclei could give a big advantage to former dopers—more nuclei means more protein synthesis, which means more muscle. So steroid use can still offer a competitive advantage years later. Which means that a clean ballplayer can still hit a dirty home run.
