A lack of deep sleep increases the risks of disease (diabetes, obesity …)
One night consists of several phases of sleep. There is the falling asleep, the light sleep phase where the brain slows down moderately, the body begins to relax, but remains easily awake and the paradoxical sleep phase marked by dreams. There is also the deep sleep phase which is the most restful moment for the body and the brain. “”During this phase, brain activity is very slowed down, breathing and heart rate are regular. The body recovers the most from the physical fatigue accumulated during the day. It is very difficult to wake up or be awake. If you get there, you are in a state of torpor called “sleep inertia”, translated into common language by “we are next to the plate, head in gas, in the cabbage“, describes Caroline Rome, sophrologist specializing in sleep and author of the book” Le Sommeil found “(ed. Solar). The first half of the night is richer in deep sleep and the second, in paradoxical sleep, which is why we have the impression of dreaming particularly in the morning.
In addition to being a recovery, deep sleep strengthens the immune system, participates in the production of hormones, increases memory and learning, develops decisions. Conversely, a lack of deep sleep can increase the risks of disease (diabetes, obesity …). So we need to have a good amount of deep sleep to be in good shape. This need varies according to age, state of health, and the overall quality of sleep: young adults often need it a little more, while the quantity decreases naturally with age.
“”In adults who do not have sleep disorders, the deep sleep phase Composes about 25% of sleep time. In other words, for an 8 hour night, you need about 2 hours of deep sleep. On a night of 7 a.m., we are rather 1:45 am in deep sleep. We will need at least that to recover well“, explains Dr. Marc Rey, neurologist and president of the National Institute of Sleep and Vigilance (INSV). Several tools exist to measure the number of hours of deep sleep, such as connected watches (Fitbit, Garmin, Apple Watch …). Applications (Sleep Cycle, Pillow …) are a little less precise than the devices worn, but are useful for an estimation. (to do in the sleep laboratory) is the most precise medical examination.
To increase your deep sleep, you need good sleep hygiene: keep regular sleep schedules as much as possible (go to bed and get up at the same time, even on weekends), avoid screens before sleeping because the blue light nights with deep sleep, avoid caffeine and alcohol after 4:00 p.m. because they disrupt the quality of deep sleep, do the regular exercise because the movement helps to sleep better and avoid heavy meals decreases deep sleep. “”A cool temperature in the room, darkness and silence promote more restful sleep“, Specifies the neurologist to us. Likewise, reading, meditation or breathing slow down the pace before night and are profitable for deep sleep.
