Maybe you didn’t get enough sleep last night, spent too much time working or preparing for that big project or presentation, or maybe you just pushed yourself too hard at the gym. Whatever the reason, you now find yourself a little more easily irritated, a little too sore, or not as focused as you were. Fatigue is nothing new- let’s face facts, it happens to all of us now and again.
Coming from the French word for ‘weariness’, fatigue, our word originates as the Latin fatigare, meaning ‘to tire out’ or ‘to cause to break down.’ Essentially, the word is the physical manifestation of stress. Whether we are talking about training a plant to grow a certain way, the frame of your car, or the reason why you are always feeling anxious, fatigue represents a deviation from “normal.” Since talking about metal fatigue on a car’s frame or training a vine to grow a certain way would probably only increase the fatigue for many, let us have a look at ourselves.
Varied occupations typically involve varied forms of stress; however, there is one particular cause of fatigue that we have all experienced at one time or another: lack of restful sleep. A survey from 2014 states that, though over half of Americans admit that they require 8+ hours of sleep, just 1 in 4 actually gets that much. And while there are ways to get more restful sleep, most people still do not place sleep that high on their list of priorities: apparently the level of fatigue is manageable for them, at least in the short term.
Usage of fatigue
The first known use of the word in English comes from Sir William Temple’s Works (1731) where, using the term synonymous with “trouble” he writes that: “The glorious Fatigues which have hitherto been the Diversion of your Highness.”
Usage of the word in relation to metals and solid objects unsurprisingly first appeared after the industrial revolution, with Frederick Braithwaite mentioning in the 1854 Proceedings to the Institution of Civil Engineers that: “Many..accidents on railways..are to be ascribed to that progressive action which may be termed the ‘fatigue of metals’.”
Looking specifically at human nature though, we can see the word’s usage go from the general sense, as Daniel Defoe wrote in 1719: “It having been a Day of great Fatigue to me,” to J. H. Bennett’s 1872 Textbook of Physiology, which, for the first time, speaks specifically of “Muscular fatigue.”
Considering how much of our understanding of the physical nature of fatigue has improved during the first century of the word’s usage, it is quite ironic that, in the almost 150 years since Bennett’s writing, we have not yet been able to deal with it.
