Monday morning, by the coffee machine, with sleepy eyes and poor morale, we hear the same mantra: « I feel so tired ».
As we have the impression of not having enough time and yet never more have we had so much time, we feel tired while we sleep no less than our ancestors. But if it is not the amount of sleep that has changed, quality of sleep and our sleep schedule have.
We are placed in the dock of this chronic sleep debt: overwork, the desire to do many things, screens, social networks, loss of meaning, etc. What is fatigue? How have we desynchronized our biological rhythms? What can we do to feel less tired? Brief history of fatigue, a symptom of our contemporary ways of living which sometimes forgets the most important things and in which screens are a substitute for a sun which never sets.
What is fatigue? Fatigue is a normal reaction to an effort, created by our body to protect us, our muscles and above all our brain. Fatigue may be physical, organic, temporary, chronic, etc. It is one of the less specific symptoms in human medicine as it is a physical and mental perception. Most of the time, this physiological phenomenon is reversible with rest. But when it is not, it does question our way of living as it is the result of the desynchronization of our inner biological clock.
But no, fatigue is not the disease of the century. Our ancestors, who worked twice the hours we do (70 hours per week on average) most often in factories or in the fields, felt tired too. But they went to bed early, did not open their Facebook app before sleeping, and above all they did not live in a society which has set up as a cool model the tireless people who manage work, children, sport, social life, leisure, without the shadow of a yawn.
For historian Anna Katharine Schaffner, fatigue has always existed throughout history. What has changed are the causes of this fatigue. Today, fatigue is the result of the pursuit of performance at all levels, and the associated lack of sleep. The result? The desynchronization of our inner biological clock, which is genetically programmed and which pushes us to respect this schedule. But this schedule is not always respected. Incriminating factors are the rise of capitalism, stress, loss of meaning at work, screens and their blue light.
Indeed the blue light of screens that suppresses melatonin, which is a hormone made in the darkness and responsible for falling asleep, is going to hurt this inner biological clock. But we know very well that the phase where sleep is the most restorative (during which the nearly all of growth hormone is produced) generally corresponds to the first three hours of cycle, precisely the ones upon which we encroach (between 23h and 2 in the morning).
So how can we prevent fatigue?
The first thing to find one’s inner biological clock again is to know it. For this, we observe our natural rhythm during vacations. Short or long sleepers, you’re warned. And when returning home from vacation, the golden rule is the following: always getting up at the same time. Believing that we catch up on lost sleep when getting up late is a good idea only at first sight. Once our ideal hours have been identified, go back to basics: we put on our sneakers because practicing sport secretes endorphins and serotonin, which plummet when we feel tired, we read a book before sleeping, go easy on coffee and alcohol and we head for healthy and varied nutrition, etc.
Finally, we question ourselves about the causes of this fatigue and we ask ourselves: how do I want to use my precious time?