People often debate whether they need seven or nine hours of sleep each night. Many studies have suggested that the average person needs around eight hours of sleep each night to function at their best.
However, there are also people who believe that they are getting 8 hours of sleep but wake up feeling tired and experiencing sleepiness during the day.
Is it that they are not getting enough sleep? So, how much sleep do you need?
The answer is that it depends on each individual needs. Furthermore, you may be getting enough sleep, but what is important is to be able to get enough deep sleep every night to allow your body to be able to heal and rejuvenate itself.
Before digging into how much deep sleep you need. It is important to understand the two types of sleep and how they are placed in the different stages of sleep.
Stages of Sleep
There are two types of sleep NREM (non-rapid eye movement) and REM (rapid eye movement). Each of these goes through 5 to 6 cyclic sleep episodes during the night.
There are 5 stages of sleep. Stage 1 to 4 comprises NREM sleep and the last one is REM sleep. The sleep cycle starts in following sequential order and the cycle is repeated throughout the night.
Stage 1: This is a stage comprising light sleep with a person aware and alert of their surrounding. The body transitions into a relaxation state with the onset of alpha waves in the brain. It lasts from 1 to 7 minutes and makes up 2 to 5 percent of your sleep. One can easily be awakened in this stage by a slight noise.
Stage 2: This is a characterized by lowering of body temperature, no eye movement with regular breathing and heart rate. The body enters into a deep sleep stage and one cannot be easily awakened in this stage. Its span increases with each cycle and lasts from 10 to 25 minutes. It makes up 45 to 55 percent of your sleep.
Stage 3: It is a deep sleep stage characterized by slow delta waves in the brain. The person does not wake up at this stage even if there is some noise in the room. Breathing further slows down and blood pressure also drops in this stage. In this stage of sleep, the body begins to repair and regenerate tissues, and it is important for physical and mental recovery. It lasts for a couple of minutes and forms 3 to 8 percent of sleep.
Stage 4: In this stage body goes deeper into sleep with even slower brain waves. This lasts for 20 – 40 minutes and forms 10 to 15 percent of sleep.
Stage 5 or REM sleep: As the name suggests, this is stage is characterized by rapid eye movements, faster breathing, increased brain activity, and muscle paralysis.
It is during this stage that dreams occur. It is thought to be important for the consolidation of memories and the regulation of mood. At first, it lasts for 1 to 5 minutes, but during later cycles, its length increases.
The above sleep architecture or stages occur in a cyclical pattern throughout the night. The amount of time spent in each stage can vary from one person to another, as well as over the course of one night.
Role of Deep Sleep
Sleep has an important role in our mental and physical well-being. Deep sleep or slow-wave sleep is an integral part of sleep with many important benefits.
Feeling Fresh and Energized
The purpose of deep sleep is to eliminate fatigue and restore energy. As a result, you wake feeling fresh and energized ready to give your best the next day.
Builds Immune System
As most of our internal processes slow down during deep sleep, more body energy is available for strengthening our immune system. Stress hormones affect our immune system and deep sleep helps to reduce the levels of stress hormones. It also helps in the production of cytokines that help in fighting infection.
Regenerate Cells and Tissues
Deep sleep also helps in repairing and regenerating new cells and tissues. It also helps in secreting growth hormone from the pituitary gland that aids in the growth of new cells and muscle repair.
Removal of Toxins
The removal of toxins also takes place in this stage which is essential for the optimal health of the brain cells.
Factors affecting Quality of Deep Sleep
Psychological Factors
A person suffering from any sleep disorder, anxiety, stress, depression, or excess energy stored in the body can affect sleep. A balanced mood promotes deep sleep and helps in improving sleep quality.
Physiological Factors
A person with excessive fatigue, some pain, itching, or respiratory problems can hinder deep sleep.
Environmental Factors
Exposure to bright light or blue light from electronic devices before bedtime can affect sleep quality. Creating a quiet and comfortable environment in the bedroom is essential for falling asleep as well as promoting restful sleep. Make sure the room temperature is optimal and slightly on the cooler side. Any noise, hot or humid environment can affect your sleep.
Work Schedules
Many individuals work in shifts. These shifts can be odd working hours and directly impact the quality of sleep. Work-related travel or jet lag can disturb your circadian rhythm. Following a regular sleep schedule regulated your internal biological clock and improves the overall sleep quality.
Caffeine
The consumption of alcohol or caffeine-related drinks should be avoided a minimum of 5 to 6 hours prior to bedtime. They directly affect the sleep schedule and disrupt the sleep cycle in a negative way. Avoiding heavy meals before bedtime should also be avoided.
Exercise
Regular physical activity and exercise are recommended for the overall health of the body and mind. It has also a direct impact on sleep. So it is essential to maintain an exercise schedule but make sure it is not close to your bedtime. As it will be counterproductive and negatively impact your sleep.
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