The different sleep cycles that make up our nights are interspersed with micro-awakenings. Some sleepers are not lacking in punctuality: every night at the same time, they spontaneously emerge from their sleep and see the same combination of numbers appearing again and again on the face of their clock. Let us explain.
Sometimes our nights are disrupted and sleep is rushed. For some sleepers, the scenario is always the same: they may go to bed at more or less the same time every day, suffering from the same level of fatigue, but their eyes always open at the same time during the night. Whose fault is this?
To understand what goes on in a body that wakes up every night, we must first look at our sleep cycles. "Each individual has his or her own cycle length (on average 90 minutes). It is formed over the years and reaches a constant value in adulthood," explains Damien Davenne, chronobiologist and professor at the University of Caen. As the night progresses, sleep becomes less and less deep, "the brain gradually resumes an activity close to wakefulness, which makes it more likely to be woken up", informs the specialist.
This rhythm of cycles explains why the time of untimely awakening is always the same. If the average sleeper goes to bed at 11 p.m. every night, it is quite possible that he or she will wake up at around 2 a.m. after the first two 90-minute cycles have elapsed.
Two to three nights are enough for the body to integrate this habit. To counteract it, the chronobiologist is categorical. "You must not break the sleep pattern. If you get up to read, to fill in pages, or to juggle your thoughts, you are telling your biological clock that you enjoy being awake at that precise time. Reactive to requests, it therefore quickly organises itself so that these activities are carried out in the best possible conditions, i.e. in full alertness."
There is nothing exceptional about the situation. We all wake up during the night - we talk about micro-awakenings - but all these pauses are not conscious: most of the time, we don't realise it. Those who do remember open their eyes and may tend to look at the numbers on their alarm clock or mobile phone. In this way, the alarm clock is immediately "marked".
Going back to sleep
If sleep fails to return, chronobiologist Damien Davenne suggests becoming aware of your body's support points by focusing your attention on certain sensations. Feeling your back sink into the sheets, or tracking the path of the air that tickles your nostrils to come and lodge in your lungs, are relaxation techniques very often used in sophrology.
And while it's easy to give in to the temptation to chew over your worries, sleep therapist Nelly Guichard recommends letting go. "The worst thing to do in this situation is to try to control your sleep." Also known as orthosomnia, the obsessive quest for perfect sleep is the number one ally of insomnia.
Beware, these annoying awake interludes are not always correlated with the sleep cycle merry-go-round. The time of the last meal, the quantity and composition of the meal are all factors that can encourage night-time awakenings. We should therefore take care not to force our stomachs to eat something too large or too rich in fat just before we go to dreamland, and not to consume energy drinks after 3pm.