Have you ever decided to go to bed early from 10 pm to prepare for a new working day but still felt tired, while there have been nights when you went to bed at 2 am and woke up at 7 am and your mind was still extremely alert?
How long does it take to fall asleep?
Normal sleep has two cycles: NREM (Non-Rapid Eye Movement: sleep without rapid eye movement) and REM (Rapid eye movement: sleep with rapid eye movement). In particular, the NREM cycle is divided into 4 stages.
Scientists have long relied on a variety of specialized devices to record the electrical activity of the brain during sleep. They analyzed the sleep physiological structure and divided the sleep cycle into four stages:
Stage 1: The first stage is drowsiness. Breathing becomes slow with a regular heart rate; blood pressure decreases; brain temperature decreases; blood flow to the brain is reduced; brain electric waves become slow; brain wave amplitude is slightly low. The sleepers are easily awake and may not be able to sleep again. They are awake until they are too tired and then fall asleep again. This stage is usually due to a quiet bedroom without a sound or due to no urination.
Stage 2: This stage lasts about 20 minutes. The sleeping person may be consciously absent-minded. Some discrete thoughts float through his head but he cannot see anything even with his eyes open. The body function drops. The brain waves now slow down and have a larger amplitude, and sometimes there are bursts of rapid waves. The eyes don’t move. The heart rate and the breathing rate slow down. The sleeping person may still be wakened up by the surrounding sounds.
Stage 3: The person who sleeps is very difficult to be wakened up. There must have been loud surrounding sounds to waken him up. Brainwave is slower than stage two. Eyes and hands are still immobile. Sometimes you do not know you are holding hands up for falling. At this stage, you begin to sleep deep. The stage appears 30 to 40 minutes after you doze off. This stage is longer in adolescents and shorter in the elderly.
Stage 4: This is the deepest sleep phase. If the sleeper is sleepwalking, it will occur during this period. Stage three and four are the deepest and best sleep stages of sleep. When waking up at this stage, the sleeper is disoriented, and his thoughts disintegrate.
After the deep sleep phase has ended, the sleeper returns to stage two and then enters the REM state. During this period, the large muscles are completely paralyzed, and the sleepers could hardly move their body, legs, and arms. Breathing becomes irregular, and oxygen consumption increases. REM is the cycle where dreams appear.
The alternation between NREM and REM cycles
Sleepers will alternate between REM and NREM (non-REM) four to six times a night with each cycle lasting an average of 90 minutes and fluctuating between 70 and 110 minutes. However, deep sleep (stages three and four of NREM) dominates only in the first two sleep cycles and rarely occurs again during the night. Therefore, after the first two sleep cycles, you may not be able to sleep deeply again. Most of the time it is only REM sleep.
However, sleeping patterns will change throughout one’s life. In the newborn period, REM sleep is more than 50% of the total sleep time. Newborns sleep 16 hours a day interspersed with short periods of waking. By four months REM sleep is less than 40% and the babies go into the first stage of NREM sleep.
In adults, the distribution of the sleeping stages is as follows:
(Phase 1: 5%, phase 2: 45%, phase 3: 12%, phase 4: 13%)
Sleep-related disorders are abnormal phenomena that occur suddenly during sleep or occur between the threshold of awakening and sleep. Sleep-related disorders often occur in stages three and four, so people with this condition often have trouble remembering the disorders they have.
The secret to a good and deep sleep
Relax your body with warm water
Taking a warm bath before bed is always the easiest way to put you to sleep. When you step out of the warm water in the bathroom to the bedroom, your body will respond by lowering your body temperature. This will slow down your metabolism and help you fall asleep faster.
Stay away from cell phones and electronic devices
If you want to eliminate sleeplessness, the first thing to remember is not using electronic devices before going to bed. According to numeric studies, blue wavelengths from smartphones and other devices prevent the production of melatonin – a hormone that helps the body sleep more easily.
Sleep in complete darkness or as dark as possible
Even the slightest light can disturb your sleep. Therefore, turn off all the lights and get rid of unnecessary lights when you go to bed. If necessary, use dark-colored curtains for windows to prevent outside light from entering.
Do not use alcoholic beverages before going to bed
Many people believe that alcohol helps the body feel more comfortable and easier to fall asleep. Alcohol may make you sleepy, but you may wake up halfway through and have trouble sleeping again. Beer and alcohol will prevent the body from falling into the deepest sleep state so that they can recover to the next day’s health.
Use the best bedding for you
A mattress of which the fabric is dry and hard, which cannot make you feel comfortable, let alone give you a good night’s sleep. Therefore, you should not choose mattresses with coarse materials or easily creased and hard fibers that are sweat-proof and less breathable.
On the market, there are many types of mattresses which suit the needs of each user such as mattresses for hip pain, mattresses for kids and mattresses for camping. You should choose a mattress that suits your needs.
Also, you should choose a pillow that is not too thin to hold the head and nape in a comfortable position. You should not choose a thick and hard one as this can cause neck pain or shoulder pain. Ideally, a pillow with a thickness of 4.5 – 5.5 inches that is soft and has good elastic is suitable.
Just by eliminating bad habits and practicing a good lifestyle, you will not get insomnia and tiredness in daily life. A proper and deep sleep is the basis for a healthy and energetic body.