Circadian rhythm, what is it?

Circadian rhythm, kesako?

This pretty, somewhat pompous name is in reality none other than “the biological clock” and allows each being to function thanks to the alternation between waking periods and sleeping periods. For humans, this rhythm lasts on average 24 hours 10 minutes without the intervention of an external element. No need to draw a picture to understand that over 24-hour days, this creates a gap.

Yes, okay, but in concrete terms what are the impacts of this gap? Numerous effects are observed, and those that emerge mainly act on:

• Wakefulness/sleep
• Cognitive abilities
• Memory
• The mood
• Body temperature
• Blood pressure
• Hormone production
• Heart rate

This is where several elements come into play to regulate this clock in order to correspond to the 24 hours we have available each day. The most powerful of these is… attention, drum roll… THE LIGHT!

Depending on its wavelength (= heat) and its intensity, the effects of light vary on the human body. Cold, intense light helps keep the body awake, increasing productivity and concentration, while warm, subdued light soothes us and promotes falling asleep thanks to the production of melatonin (sleep hormone).

The circadian rhythm is closely linked to the light flows that we receive daily, which is how light hygiene appeared. We do not intend to receive the light adapted to different times of the day. To maintain this light hygiene, several recommendations are made:

• turn off screens 1 hour before going to bed
• limit light pollution thanks to total darkness at night
• maintain regularity in bedtime
• expose yourself to direct light for at least 1 hour a day
• adapt your lighting according to your activity

These recommendations are not exhaustive, we are always listening if you have others to share with us!