During the back-to-school period, we are always very attentive to the biological rhythms of children, forgetting a little quickly that adults also need to take care of themselves! “It is sometimes more difficult for them to return to working hours after the summer break than for children. As you get older, past 45 or 50, it’s a challenge to resynchronize yourself, because the biological clock is less flexible,” confirms Damien Davenne, chronobiologist at the University of Caen and member of the scientific council of the Institut national du sleep and alertness.
The biological clock is this little structure nestled in the brain, the suprachiasmatic nucleus, which sets the pace for the whole body. Programmed on a cycle of approximately 24 hours, it synchronizes throughout the year according to the perceived light intensity and the alternation of day and night. It is she who will be the great organizer of our return in good shape – or not – to the office.
A more complicated return for certain profiles
Indeed, adults are not all equal when it comes to the rhythms imposed by professional life or by the school life of their children. “Each of us lives under the influence of our chronotype. The biological clock is not set for everyone in the same way on the time scale”, explains Damien Davenne. Some people are genetically programmed to be “night owls” or “early risers”, others have intermediate profiles. These are the most numerous. “Nearly 50% of the population falls asleep naturally between 11 p.m. and midnight, and wakes up around 7 or 8 a.m.,” continues Damien Davenne.
The alarm clock, the key to a successful synchronization
But when should you start preparing for back to school? A week to ten days before is the ideal window. Those who would like to prolong their summer lifestyle at all costs must plan at least two or three nights of acclimatization, before D-Day, just to limit the damage. “Awakening is the key to a successful resynchronization. To recalibrate effectively, you have to be uncompromising with yourself and slowly but surely go back up a quarter of an hour or half an hour, every day, the moment you leave your bed, ”explains Damien Davenne. And no question of lying down, half awake, after stopping the ringing, you really have to get up.
The biggest mistake would be to hoard in the mornings before the start of the school year, imagining that you are building up a stock of sleep – a bit like you would with food in anticipation of difficult days. “It is a counter-productive method, because the most restorative hours for the body are those of the beginning of the night”, explains the scientist.
Don’t sleep in on weekends
To last in the long term, it is important not to count on sleeping in. They abruptly tell our biological clock that it got its wake-up time wrong the rest of the week. The organization will pay him for several days. So getting up after 10 or 11 a.m. on Sunday sabotages waking up on Monday, leaving you feeling tired. “Hence the classic expression ‘It’s going like a Monday’ around the office coffee machine,” laughs the chronobiologist. This disruptive effect of the biological clock is still measured on Tuesday mornings. You often have to wait until Wednesday to finish paying for the negative effects of sleeping in on your morning freshness.
Once flunked, hold on!
To keep fatigue at bay, the secret is simply to maintain a good sleep regularity. Our nights are not elastic at will. “Good health is synonymous with a constant sleep-wake cycle, which does not derail the biological clock. Many adults are unaware of this or have not taken full measure of the influence of regular nights on their general condition. We are talking about daily cognitive and physical performance, as well as the risk of long-term development of cardiovascular, metabolic diseases or even cancers, “says the chronobiologist.
Fortunately, there is about an hour of leeway to allow yourself a mini sleep in, without desynchronizing your biological clock. For example, you can wake up at 8 a.m. on weekends instead of 7 a.m. on weekdays, without paying the price on the following days.
The second week, the most tiring
Back to school is not necessarily the most difficult time to go through. Indeed, “fatigue is felt more readily during the second week after the end of the vacation. The repercussion of the change of pace manifests itself with a slight delay”, warns Damien Davenne. Fortunately, this state is transitory. If you bet on a good regularity of sleep, the form will return quickly.
Just as there are recommendations for establishing a bedtime ritual that makes it easier to fall asleep, you should think about adopting an awakening ritual that will keep the biological clock workings: not lying around in bed, stretching, taking a coffee, stand next to the window, or even go for a quick walk outside in the garden… The clock perceives daylight in the morning, and thus calculates the period of wakefulness and sleep that we will need. In the evening, she will send sleepy signals prompting us to go to bed, such as itchy eyes, body temperature dropping slightly, etc.
Quickly think about your next vacation
Without always being aware of it, the months of October and November correspond to the period of the year when our body needs the most vacation. With the combination of shorter days and the transition to winter time, our biological clock is put to the test. Our body adapts by demanding more sleep. In our latitudes, it may be necessary to increase the length of our nights by one to two hours until February. In the Far North, the Inuit have extremely short nights in the summer – barely a handful of hours –, then adopt very long sleeps, going up to fourteen hours at a stretch, in the heart of winter. Humans, depending on their environment, are therefore subject to a natural adaptation process. Even if we find it difficult to accept it in our modern societies. As fatigue sets in in the fall, many don’t have the instinct to simply go to bed earlier.
Generally speaking, “we should alternate between seven weeks of activity followed by ten days of vacation. That would be ideal,” recommends Damien Davenne. In the meantime, don’t hold back from planning your next vacation. On the contrary ! An American study confirms that people who anticipate are the happiest. The feeling is growing as the long-awaited date approaches. Thinking about your next days “off”, leafing through travel guides, choosing a ticket or selecting hotels, is to follow a clear path to happiness and rest.