Understanding sleep

Our bodies are subject to a biological rhythm, known as the circadian rhythm, which is based on a 24-hour cycle. This biological cycle exists in all living beings and plays an important role in many biological, physiological and behavioural mechanisms.

Circadian rhythms

The body's functions, such as wakefulness/sleep, blood pressure, body temperature, hormone production (e.g. cortisol, melatonin), alertness and memory, are regulated by the circadian cycle.

The study of circadian cycles is called chronobiology. The term ‘circadian’ comes from the Latin terms circa (about) and dies (day). Circadian rhythms are endogenous, generated by the body itself.

The term ‘biological clock’ is used to describe this internal temporal mechanism. It acts like an orchestra conductor, imposing its rhythm on the body. Our biological clock is also sensitive to external phenomena: daylight, socio-professional activity, meals or physical activity act as signals and ‘resynchronise’ our biological clock. These synchronisers enable each individual to adapt to their environment.

It is light that has the greatest influence on our biological clock, and in particular on whether we fall asleep or are awake.

The secretion of melatonin, known as the "sleep hormone," is typically circadian, controlled by our internal clock. It increases at the end of the day (before bedtime) in the absence of light and drops in the early morning. However, exposure to light late in the evening or too early in the morning disrupts melatonin production; falling asleep may be delayed and waking up earlier may occur. The body must therefore adapt to these shifts (time changes, travel abroad).

Melatonin is also known to reduce the effects of jet lag.

The sleep cycle

We spend a third of our lives asleep¹. Sleep is essential for maintaining the proper functioning of physiological functions (regulating mood, maintaining wakefulness, etc.). The need for sleep is an individual concept, ranging from six hours to ten hours a night for “heavy sleepers”; on average, an adult needs eight hours of sleep a day².

The sleep cycle is made up of 4 stages. Each cycle lasts around 90 minutes, and a night is made up of 3 to 5 successive cycles:

1. Falling asleep : Brain activity slows down a little.
2. Light slow wave sleep: The sleeper is woken by the slightest noise (stages 1 & 2).
3. Deep slow wave sleep: Brain activity slows further. The sleeper is insensitive to noise and vital functions are minimised (stage 3).
4. REM sleep: This is a state in which the sleeper is difficult to wake up, their muscle tone is abolished but their brain is as active as it was at the beginning. 80% of dreams take place during this phase.
5. Latency (waking): Awake phase, the sleeper is more or less conscious. They may wake up or switch to another cycle.

Age-related sleep problems

More than two-thirds of people over the age of 45 have trouble sleeping³: difficulty falling asleep, waking up at night or too early in the morning... This is often the result of reduced production of melatonin, the natural sleep hormone, which occurs with age, due to calcification of the pineal gland.

Melatonin peaks at around 2 a.m., gradually levelling off with age and may even disappear in the over-70s, with nocturnal melatonin concentrations no higher than those observed during the day.

This decrease can lead to difficulty falling asleep at bedtime, frequent and prolonged awakenings that fragment the night and waking up too early in the morning, with the feeling that the night is too short.

Melatonin in chronoliberation for a full night's sleep

In the event of impaired sleep, melatonin supplementation is the best way to restore quality sleep and avoid drowsiness during the day.

A rapid and then prolonged release of specially adapted active ingredients is ideal for a full night's sleep, acting on the different phases of sleep:

• Helping you fall asleep at bedtime. The beneficial effect is obtained by consuming 1 mg of melatonin before bedtime.
• Reduce night-time awakenings, improve sleep quality and sleep better by reducing sleep problems.
• Avoid early awakenings in the morning.

This helps you sleep better, get a good night's sleep and wake up feeling refreshed.

The combination of active ingredients such as sleep-enhancing plants and sustained-release melatonin is an effective way of promoting a good night's sleep and improving the quality of your sleep.

Simple lifestyle rules to help you get a good night's sleep

TO DO

TO AVOID

Respect natural light, especially in the morning. Take part in sporting activities to help you feel tired at bedtime. Take naps of no more than 20 minutes (to avoid encroaching on your night's ‘sleep capital’). Favour soothing activities and relaxation. Create a sleep-friendly environment (calm, cool, with no lights or television). Only go to bed when you feel like it. If you have trouble falling asleep, get up and go back to bed only when sleep returns.

Excitants after 4 p.m. (coffee, tea, cola, vitamin C, etc.). Heavy meals that are difficult to digest, especially in the evening. Intense physical or mental exercise (one hour before bedtime). Screens that reproduce daylight and disrupt sleep. Don't miss your bedtime. If you're awake for a long time, don't stay in bed thinking about problems and constantly checking the time.

 

Did you know?

The blue light emitted by screens for backlighting activates the retina's non-visual photosensitive receptors a hundred times more than white light from a lamp. What's more, it sends the wrong signals to our brain and disorients our biological clock at nightfall because it inhibits the secretion of melatonin.

To help you get a good night's sleep and sleep better, it's best to switch off mobiles, tablets, computers and televisions after 9 p.m.