新托福考试阅读练习材料：A Scientist in the Locker Room

本文是一篇典型的托福阅读材料，大家可以当做模拟题测试一下：

How do you improve at any sport? You train, train, train.

But how you train is just as important as how much. Armed with the science of exercise physiology, today’s olympic-class coaches design sophisticated programs for their athletes.

A muscle is like an engine, and the fuel it runs on is the chemical ATP. Our bodies have three separate systems for creating this fuel however. Exercise physiologists pay close attention to how an athlete’s ATP is produced.

The phosphocreatine system gives an athlete lots of ATP very fast, but it’s only good for about ten seconds before it needs to recharge. The second system, called glycolysis, provides a more steady supply, but too much glycolysis can make the muscles inefficient. The third system, called aerobic metabolism, burns fats and sugars to make ATP. Aerobic metabolism is best for long term endurance, but it’s slow to get going, and, like the other systems, it also runs out of steam.

Olympic trainers take these systems into account. A long- distance runner should use aerobic metabolism for as much of her ATP as possible. To ensure this, she’ll be tested on a treadmill to measure her threshold of aerobic metabolism. The trainer then develops a training program which will increase it. On the other hand, a weight lifter should use his phosphocreatine system, which provides maximum ATP in short bursts of time. His work- outs will build up the enzymes of this system, as well as build up his muscles.

That’s just one way athletes can get a boost from the science of exercise physiology.

译文：

你怎样才能在体育运动方面有所提高呢?你不停地锻炼。

但是你怎样锻炼与锻炼量的多少同样重要。以运动生理学为指导，今天奥林匹克级别的教练为他们的运动员设计了一系列复杂的程序。

肌肉就像一个引擎，它的"燃油"是化学物质三磷酸腺苷，我们身体有3个制造这种“燃油”的独立系统。运动生理学家门密切关注了一个运动员三磷酸腺苷是怎样形成的。

磷酸肌酸系统能够非常快的为运动员提供许多三磷酸腺苷，但是在再次补给之前，这中物质只能持续大约十秒钟。第二系统，称为醣酵解，能够提供更稳定的供应。但是过多的醣酵解会让肌肉效率低下。第三系统，叫做有氧代谢，燃烧脂肪和糖分来制造三磷酸腺苷。有氧代谢有利于长期的耐力训练，但是它的反应比较慢，而且就像其他的系统样，它同样会很快的筋疲力尽。

奥林匹克教练考虑了所有的这些系统。长跑运动员应该尽可能的像运用三磷酸腺苷那样来运用有氧代谢。为了确保这样，她将会在跑步机上来测量她的有氧运动的极限。然后教练研发了可以增加有氧代谢的运动程序。另一方面，举重运动员可以运用磷酸肌酸系统，它能够在较短的爆发时间内提供最大值的三磷酸腺苷。由此将会增加这个系统的酶，也能够重塑他的肌肉。

这就是一个运动员从运动生理学上获得提高的路径之一。