When you have a good night’s sleep, you wake up feeling energetic, refreshed and ready to start your day. Sleep affects not only your productivity at work but also your physical appearance. It can even impact your overall quality of life. Sleep can be divided into two broad stages, Non-Rapid Eye Movement (NREM) and Rapid Eye Movement (REM) sleep. Majority of our sleep is NREM, this is the time when we are in deep sleep. The first part of the cycle is NREM sleep which composed of 4 stages.
Stage 1 (1-7 minutes): The earliest stage of sleep where you are drifting off, somewhere between wakefulness and slumber. It is easy to get awoken as your brain is still quite active and you might even feel that you’ve not slept at all. Your eyes move slowly back and forth as your muscles relax. Your eyelids feel heavy and your head starts to drop. The electrical activity on an electroencephalogram (EEG) monitor starts to slow down, and the cortical waves become taller and spikier.
Stage 2 (10-25 minutes): After a few minutes, your brain activity slows further and you descend into light sleep. Philip Gehrman, Ph.D., assistant professor of psychiatry at the University of Pennsylvania, dubs stage two sleep “average sleep” — It is not too deep, yet not too light. You become more detached and lose a sense of your surroundings, your heart rate and breathing regulate and body temperature drops. Your heart and vascular system are getting their much-needed rest and brain waves are slow with some rapid bursts known as ‘sleep spindles’. At this stage, your eyes stop moving but you are still easily awoken.
Stage 3 (20-40 minutes): As you enter this stage, sleep spindles halt and you enter moderate sleep, which is followed by deep sleep. Brain waves are slow with high amplitude. These brain waves are known as delta waves. As you progress through this stage, you become much more difficult to wake up. According to the National Sleep Foundation, your blood pressure starts to drop, breathing slows down, blood flows to the muscles and tissue is repaired during this restorative stage of sleep. Hormones, such as the human growth hormone, are secreted at this time as well.
Stage 4 (20-40 minutes): Stage 4 is the deepest of sleep where you are extremely difficult to be awoken. The EEG shows tall and slow waves, making jagged pattern on the EEG. Your muscles relax and your breathing becomes slow and rhythmic, which can lead to snoring. This stage is also where parasomnias, such as sleep walking, talking or eating, take place. The first period of deep sleep is the deepest. The sleeper awakened from deep sleep will probably feel groggy, confused or disoriented and might not be able to function for quite some time. About 20 percent of the night is spent in deep sleep, and it mostly happens in the first half of the night.
REM Sleep: After deep sleep, your brain starts to perk up, and its electrical activity starts to resemble the brain when it is awake. Your eyes start to move rapidly behind closed lids and breathing and heart rate increase. REM sleep is where you will see vivid, imaginative dreams. At the same time, muscle groups become paralyzed to prevent you from acting out your dreams. The EEG shows low-amplitude, mixed frequency waves called theta waves, with some alpha waves.
The cycle then repeats itself, but with each cycle you spend less time in the deeper stages three and four of sleep and more time in REM sleep. On a typical night, you’ll cycle through four or five times. Most of your deep sleep happens in the first half of the night while most of your REM sleep happens in the second half.
A good night’s sleep is extremely important for health no matter how old you are. If you do not know the benefits of a good sleep, continue reading to find out more!
1. Good sleep can improve productivity and memory
Good sleep can improve problem solving skills and enhance memory performance of both children and adults. When you have a good sleep, your body is resting while your brain is actively sorting and storing memories. This will help to recall and process things better. If you are learning a new skill such as sports or language, you tend to do better after sleep.
Researchers at Harvard University and Boston College found that a good night’s sleep can help to consolidate memories and make them stronger, which may result in more creativity.
2. Sleep improves your immunity
Protein molecules are produced by your body during sleep. This helps to strengthen your ability to fight infection. To improve immunity, you should get at least 8 hours of sleep every night.
3. Sleep affects your social and emotional interactions
Lack of sleep reduces our ability to communicate and interact socially. It affects our ability to recognize important social cues and process emotional information.
4. Sleep helps to reduce stress
When your body doesn’t get sufficient rest, it will react by producing an elevated level of stress hormones. Deep and regular sleep can help to prevent this.
5. Good sleep can maximize athletic performance
Longer sleep is shown to improve speed, accuracy, reaction times and mental wellbeing. People who sleep more also have less daytime fatigue and better stamina.
And the negative flipside of not enough sleep is clear too. As leading health guide, Healthline, highlights “A study of over 2,800 women found that poor sleep was linked to slower walking, lower grip strength, and greater difficulty performing independent activities.”
As such, a good sleep is important as it improves many aspects of athletic and physical performance.
6. Sleep can lower your blood pressure and risk of heart diseases
When you are sleeping and relaxing, blood pressure is lowered and kept under control, thus lowering the risks of heart attacks and strokes.
7. Sleep can help you maintain your weight
Poor sleep is strongly linked to weight gain. Studies have shown that people who are sleep deprived have a bigger appetite and tend to eat more calories.
Researchers at the University of Chicago found that dieters who were well rested lost more fats than those who were sleep deprived, who lost more muscle mass.
Sleep deprivation disrupts the daily fluctuations in appetite hormones and is believed to cause poor appetite regulation, leading to overeating and obesity.
8. Sleep makes you happier
A lack of sleep affects your emotional regulation and will make you more agitated and grumpy. The better you sleep, the more you are able to remain composed, calm and reasonable.
9. Sleep affects your lifespan and quality of life
Getting a good night’s sleep won’t prevent you from diseases but a lack of sleep can cause serious health problems like heart disease, diabetics and obesity, which in turn affects your lifespan and quality of life.
10. Sleep can be a pain killer
A good night’s sleep can supplement medication for pain. If you are suffering pain from a recent injury, getting lots of rest can make you feel less painful.
11. Poor sleep is related to depression
Mental health issues such as depression are strongly linked to poor quality sleep and sleeping disorders such as insomnia or obstructive sleep apnea. A good night’s sleep can help a moody person reduce their anxiety and improve emotional stability.
12. Poor sleep is linked to increased inflammation
Poor sleep has been strongly associated to long-term inflammation of the digestive tract, in disorders known as inflammatory bowel diseases. In addition, research has shown that people who sleep less than 6.5 hours a night have higher blood levels of inflammatory proteins.