［美］戴尔卡耐基/Dale Carnegie
我为什么要在一本谈论排忧的书里写有关避免疲劳的问题呢？原因很简单，因为疲劳常常会带来烦恼，至少会使你容易感到烦恼。任何一个医科学生都会告诉你，疲劳会降低身体对普通感冒和其他上百种疾病的抵抗力。任何一位心理学家都会告诉你，疲劳会降低你对恐惧和烦闷的抵抗力。所以，避免疲劳有助于避免忧虑。
我刚才说“可以避免忧虑”吗？这句话表达得缺少力度。芝加哥大学实验心理学实验室主任埃德蒙？雅各布解释得更明确一些。他写了两本有关放松的书——《消除紧张情绪》和《放松紧张情绪》。多年来，他一直在临床实践中运用放松紧张情绪的方法，并进行了相关方面的研究。他声称，任何精神或是情绪的紧张状态“在完全放松的状态下就会消失”。换句话说，如果你处于放松状态，就不会再忧虑了。所以，为了避免疲劳和忧虑，第一条规则就是：经常休息，在你感到疲倦之前休息。这一条为什么很重要呢？因为疲劳的累积速度快得惊人。美国陆军经过反复试验得出：受过多年军事训练的年轻人，如果他们丢下包，每小时休息10分钟的话，他们的行军速度会很快，并能持续很长时间。所以，陆军部队强制他们要这样做。
你的心脏与美国陆军士兵的心脏一样健康。心脏每天为你身体提供的血液，你的心脏24小时内所提供的能量足以把20吨煤铲到3英尺高的月台上。心脏承受如此大的工作量，要持续五七十年甚至九十年，心脏是如何承受的呢？哈佛医院的华特？坎农博士解释说：“大多数人都认为心脏是在一直不停地工作。事实上，心脏每收缩一次，都会停止一段时间，再以每分钟70次的速度跳动。24小时中，心脏的实际工作时间仅有9小时，每天的休息时间总计长达15小时。”体力劳动者如果每天有足够的时间休息，那么，他就可以干更多的活。弗雷德里克？泰勒在伯利恒钢铁公司担任科学管理工程师期间，通过观察发现：每个工人每天往货车上搬运12.5吨生铁，到了中午，他就筋疲力尽了。弗雷德里克？泰勒对导致工人疲劳的因素作了一次科学研究。他认为，这些工人每天不应只装运12.5吨生铁，而是47吨。他认为，工人们应该创造的工作量至少是现在的四倍。不过，我们要证明一下。
泰勒挑选了施密特先生，要求他按秒表的时间工作。施密特让一个人拿着表站在他身边：“现在开始搬运生铁，走……现在坐下来，休息一会儿……现在走……现在休息。”发生了什么呢？普通工人每天只搬运12.5吨生铁，而施密特一天搬运了47吨。而且，他在伯利恒钢铁公司工作的三年里，工作能力并未下降过。施密特能够做到这样，是因为他在感到劳累之前就休息了。他每工作26分钟，就要休息34分钟。他的休息时间要长过工作时间，但工作量是其他人的四倍！这是传言吗？不是，你可以阅读一下弗雷德里克？泰勒的《科学管理法则》。让我再重复一遍：按照陆军的方法去做——频繁的休息；按照心脏的跳动规律去做——在感到疲劳之前就休息。这样，你每天的清醒时间就会增加一小时。
Why am I writing a chapter on preventing fatigue in a book on preventing worry？That is simple：because fatigue often produces worry，or，at least，it makes you susceptible to worry.Any medical student will tell you that fatigue lowers physical resistance to the common cold and hundreds of other diseases and any psychiatrist will tell you that fatigue also lowers your resistance to the emotions of fear and worry.So preventing fatigue tends to prevent worry.Did I say“tends to prevent worry”？That is putting it mildly.Dr.Edmund Jacobson goes much further.Dr.Jacobson has written two books on relaxation：Progressive Relaxation and You Must Relax，and as director of the University of Chicago Laboratory for Clinical Physiology，he has spent years conducting investigations in using relaxation as a method in medical practice.He declares that any nervous or emotional state“fails to exist in the presence of complete relaxation”.That is another way of saying：You cannot continue to worry if you relax.So，to prevent fatigue and worry，the first rule is：Rest often.Rest before you get tired.Why is that so important？Because fatigue accumulate with astonishing rapidity.The United States Army has discovered by repeated tests that even young men—men toughened by years of Army training—can march better，and hold up longer，if they throw down their packs and rest ten minutes out of every hour.So the Army forces them to do just that.
Your heart is just as smart as the U.S.Army.Your heart pumps enough blood through your body every day to fill a railway tank car.It exerts enough energy every twenty-four hours to shovel twenty tons of coal on to a platform three feet high.It does this incredible amount of work for fifty，seventy，or maybe ninety years.How can it stand it？Dr.Walter B.Cannon，of the Harvard Medical School，explains it.He says，“Most people have the idea that the heart is working all the time.As a matter of fact，there is a definite rest period after each contraction.
When beating at a moderate rate of seventy pulses per minute，the heart is actually working only nine hours out of the twenty-four.In the aggregate its rest periods total a full fifteen hours per day.”A physical worker can do more work if he takes more time out for rest
.Frederick Taylor demonstrated that while working as a scientific management engineer with the Bethlehem Steel Company.He observed that labouring men were loading approximately 12 1/2 tons of pig-iron per man each day on freight cars and that they were exhausted at noon.He made a scientific study of all the fatigue factors involved，and declared that these men should be loading not 12 1/2 tons of pig-iron per day，but forty-seven tons per day！He figured that they ought to do almost four times as much as they were doing，and not be exhausted.But prove it！Taylor selected a Mr.Schmidt who was required to work by the stop-watch.Schmidt was told by the man who stood over him with a watch：“Now pick up a‘pig’and walk...now sit down and rest...now walk...now rest.”What happened？Schmidt carried forty-seven tons of pig-iron each day while
the other men carried only 12.5 tons per man.And he practically never failed to work at this pace during the three years that Frederick Taylor was at Bethlehem.Schmidt was able to do this because he rested before he got tired.He worked approximately 26 minutes out of the hour and rested 34 minutes.He rested more than he worked—yet he did almost four times as much work as the others！Is this mere hearsay？No，you can read the record yourself in Principles of Scientific Management by Frederick Winslow Taylor.Let me repeat：do what the Army does—take frequent rests.Do what your heart does—rest before you get tired，and you will add one hour a day to your waking life.
