From federal investigations into Major League Baseball to allegations ofsubstance abuse in track and field, performance enhancing drugs have been in the news a lot.
从对美国职业棒球大联盟药物滥用指控的联邦调查来看，服用兴奋剂已经成为一个热门话题f56~d,GcK^T。
The most well-known performance enhancers are steroids, drugs that can make athletesbigger and stronger.
其中最著名的兴奋剂是类固醇，它可以让运动员更大更强bo%W1R=zbg=3.。
But they can also cause serious medical problems.
但是它们也会导致严重的医学问题nikW4oiOJ;_Dw%k*。
So how do steroids work, and what makes them so dangerous?
那么类固醇是怎样发挥作用的呢？是什么使它们如此危险？

First, it’s important to understand that the body naturally produces steroids.
首先，知道身体能够自然产生类固醇是很重要的;WdxjL4~p2|。
For men, the best known is testosterone.
对于男性来说，最广为大家所知的就是睾丸激素4KbS*|b0-^。
Testosterone is an anabolic steroid,meaning that itencourages new muscle growth.
睾丸激素是一种合成代谢类固醇，它能够促进新的肌肉的生长!oq*|LnZdx%|)t]Trpa。
So the more testosterone you have in you, the greater potential youhave to be bigger and stronger.
因此如果你的睾丸激素越多，你的潜力就越大越强fh|m4.Mx_Y。这样一来，人造合成类固醇
It makes sense, then, that artificial anabolic steroids mimic testosteroneproduced in the body.
模仿人体内分泌的睾丸激素应运而生了;@(rL,mGk)。
Here’s how they work.
它们是这样工作的kwie(bfhEO(ksZ。
Anabolic steroids attach to cells and encourage them to produce more protein,which muscles need to grow and become stronger.
合成类固醇依附于细胞上，促使它们产生更多肌肉生长和壮大所需要的蛋白质NIGRjJ+G32TWBA6。
So steroids basically speed up and enhance theprocess of muscle growth that you can accomplish by lifting weights and other kinds of exercise.
因此类固醇主要是加快和加强肌肉生长，而这样的效果你可以通过举重和其它的运动练习达到05Z=N.5W2lH.O。
Aweightlifter on steroids will develop larger muscles and do so faster than a “clean” weightlifter.
一个服用类固醇举重运动员的肌肉会比一个“干净”的运动员生长得更大更快o9_w2.V#]*FPT@Ek。
Millions of people take performance enhancing drugs such as caffeine and vitamins every day.
成千上万的人们每天都在服用咖啡因，维他命之类的兴奋剂A*s&)pG6j6Y6-J7UVw]=。
But unlikethese drugs, steroids can cause serious, long lasting problems.
但是与其它药物不同的是类固醇会导致严重，持久的问题h~4IhHShIY。
For example, steroid use puts extrapressure on the liver to cleanse the bloodstream of the many toxins in steroids.
例如，使用胆固醇会对肝脏净化血液带来压力，因为胆固醇里有很多毒素djA|l@n&|-x7x07Zc)。
Prolonged steroid use can result in liver damage.
长期使用类固醇可导致肝损害_bQbKlwoiBFujhk%,#k。
They also affect brain chemistry,and cancause depression and severe mood swings known as roid rage.
它们同样会影响脑化学，并会导致抑郁症和被称为“类固醇癫狂”的严重情绪波动82F[_K0sqdxC4mMmTN。
There’s certainly nothingwrong with building your body, but using steroids to do so will ultimately break you down.
强身健体当然没有错误，但是如果你使用类固醇来完成，那么最终你会垮掉QEt0pnn75pJZkKz+。