Fatigue Study and Waste. In “Motion Study” we stated: “There is no waste of any kind in the world that equals the waste from needless, ill-directed, and ineffective motions.”[1] It is an aspect of wasted motions that we are discussing here. Wasted motions mean wasted effort and wasted time. One of the results of this waste is unnecessary fatigue, caused by unnecessary effort expended during time that must, as a result, be wasted. Time, a lifetime, is our principal inheritance. To waste any of it is to lose part of our principal asset. To waste time and to suffer from unnecessary fatigue simultaneously can be excused only by ignorance. Unnecessary fatigue is caused by some one’s ignorance. This book aims to call the attention of the world to the relationship between fatigue and waste, with the hope that the knowledge of our methods of fatigue elimination may be useful to others. What Fatigue Is. A crowd of workers come out of the factory after the day’s work. Some rush home; others walk at a leisurely pace. Some move slowly and with effort. Some have their heads back and a satisfied expression on their faces. Others have their heads bent forward, and look as though life were not worth while. What is the difference between the members of this group? Mainly a matter of fatigue. Fatigue is the after-effect of work. It is the condition of the worker’s organism after he has expended energy in doing something. It is a necessary by-product of activity. If, as is presumable, every member of our crowd of workers has been putting in a day full of activity, we might expect to see the same marks of fatigue on every face and figure,--but we do not. What, then, are the reasons for the difference? The state of fatigue has only been systematically studied during the past thirty years. Even to-day it is not wholly understood. We do know, however, several things about it, that may explain what we see in the emerging group. We know that fatigue is marked by a decrease in power to work, a decrease in pleasure taken in work, and a decrease in the enjoyment of the hours spent away from work. We know that exertion not only uses up temporarily the energy of the body, but that it also seems to generate a sort of poison which “slows one down” for the time being. In the third place, we know, also, that the effects of fatigue are more difficult to overcome as the fatigue becomes greater. Careful observation and records show that a little fatigue is easily overcome if proper rest is supplied immediately. Twice the amount of fatigue requires more than twice the amount of rest. Four times the amount of fatigue demands much more than twice as much rest as the preceding “more than twice the amount of rest,” until, finally, a state of excessive fatigue requires a rest period that might have to be prolonged indefinitely. It is this fact that lies at the basis of the great unnecessary waste in accumulated fatigue.