Sleep is a primary need, just like eating and drinking. Too little, too much and/or poor quality sleep impacts our health directly. When we sleep, breathing and heart rhythms slow down, muscles relax, consciousness decreases and the brain isolates us from exterior stimulation.
During sleep, several recovery and building processes take place in both body and mind. Sleep is made up of five cycles, each of about 90 minutes. Each cycle is made up of five phases.
The phases are differentiated by brain activity and eye movement: in four out of the five phases, there is very little eye movement.
Phase 1: Light sleep, when you start falling asleep, brain activity slows, eye movements are slow. For a night with five cycles this represents 2-5% of total sleep.
Phase 2: The start of real sleep, but still light. Sounds no longer don’t wake you but if someone wakes you up, you don’t feel rested. For a night with five cycles this represents 45-55% of total sleep.
Phase 3: Passing to deep sleep, breathing slows and becomes completely regular, heart rhythm slows and muscles fully relax. Phase 3 represents 3-8% of a full night with five cycles.
Phase 4: Real deep sleep. If woken now, you feel disoriented and need time to work out where you are. This phase is essential for physical recovery and represents 15-20% of a total of five cycles.
The deep sleep phases (3 & 4) are of key importance for physical and brain recovery.
Phase 5: Characterized by Rapid Eye Movement and therefore known as REM sleep. REM sleep is considered dream sleep, when the brain is active. Breathing and heart rhythm are irregular and this phase takes energy. REM sleep represents 20-25% in a full five cycle night.
After phase 5 you normally wake up briefly (often unconsciously) and a new cycle starts.
Our natural sleep rhythm is based on the daily light/dark cycle. The total amount of sleep needed varies from person to person; on average an adult needs about 7-8 hours of sleep per day.
Lack of sleep occurs when numerous cycles aren’t achieved.
In its early stages, lack of sleep is associated with reduced productivity, poor concentration and increased irritability, and it compromises recovery after training. Lack of sleep is cumulative: the more nights with insufficient sleep, the more likely that negative effects will occur.
Chronic lack of sleep may lead to reduced immunity, weight gain and increased risk of developing type 2 diabetes and heart disease and is considered a serious health risk.
Though sleep deprivation is often associated with work and/or other stress levels, most people don’t sleep enough out of choice – watching TV, browsing the internet, or going out with friends. If we were to remove artificial stimulation and excessive work/life demands, most humans would sleep about eight hours per night, based on the natural sleep/wake cycle of the brain.
What can we do to improve our sleep quality?
– Keep a relatively consistent bed and wake time
– Make sure you keep your bedroom as dark and quiet as possible
– Keep your bedroom at a slightly cool temperature and well ventilated
– Empty your head, write a to-do list for the next day before you go to bed
– Avoid drinking alcohol before going to bed: it may help you sleep in, but compromises the quality of your other sleep
– Do not eat a big meal shortly before going to sleep
– Avoid caffeinated drinks or other stimulants in the evening
– Take a warm shower or bath just before going to bed
– Do something relaxing before you go to sleep: read a few pages, drink some warm milk
– Do not watch TV or work on a computer or tablet for at least half an hour before going to sleep: screens are light sources and put your brain into wake mode
– Exercise will tire you physically, but do high intensity exercise during the day or at least a couple of hours before going to bed
– Taking a little walk or doing relaxation exercises just before going to bed is an excellent idea
Anco Wijbinga, Well-being Manager at Aspria Royal La Rasante
