We all know how refreshing a good night’s sleep can be for both body and mind, but have you ever asked yourself „how much sleep do I need” and „what exactly happens while I sleep”? Read on to find out.
There are 4 stages of sleep that people can experience, namely stages 1, 2 and 3 (known as non-REM sleep), and REM sleep. You begin at stage 1 and go through all of them in a complete cycle of about 90 to 110 minutes, then start over. Each of the individual stages lasts no more than 15 minutes.
Stages 1 and 2 are light sleep, while stage 3 is deep sleep. These total 4 to 7 hours per night, whereas REM sleep is only about 1,5 to 2 hours in total per night, which can already give you a rough idea of how much sleep do you need.
This is the lightest sleep stage, characterized by slow eye movements and a slowing down of brain wave and muscle activities. During this transition stage, you can wake up at the slightest noise, often without even realizing you were asleep to begin with. Moreover, because of the muscle spasms that may occur, you may feel like falling.
This is the main stage of light, non-REM sleep. Your eye movements stop and you won’t wake up as easily, while your body temperature and heart rate slowly drop. This is the time when you organize and store your memories. Although brain waves keep slowing down in stage 2, there are bursts of activity that presumably help the brain stay asleep.
This is the deepest part of sleep and the one that is the most restorative. It is difficult to wake someone up from stage 3 sleep. Sleep disorders or parasomnias, such as sleep paralysis or sleepwalking, can take place at this stage.
REM stands for rapid eye movement, and this is exactly what happens during this sleep stage. The activity of brain waves begins to pick up, resembling that of when you are not sleeping. We dream during the REM stage, and our muscles are locked down to prevent us from getting injured while trying to move according to the dream. You can wake up or be awaken more easily at this point, but when that happens, you are likely to feel dazed or very sleepy.
So how many hours of sleep do you need? This varies with age and depends on your sex and health, but generally 7 to 9 hours of sleep are enough for an adult needs. This being said, children need more sleep, while older people require a minimum of 7 hours per night.
More specifically, according to The Sleep Council in the UK, babies up to 1 year of age require the most sleep time: 14 to 15 hours per day. The amount gradually decreases from kids aged 1 to 12 years old, reaching 10 to 11 hours of daily sleep. People aged 12 to 65 need between 7 and 9 hours of bedtime, while those over 65 only require 7 - 8 hours per day.
Now that you’ve got the answer to your „how much sleep do I need” question, the next logical one is „why?”
The answer is simple: your body and mind needs to go through all 4 stages of sleep every night, repeated 5 or 6 times, to ensure everything is in good working order internally and that you get enough rest to start over the next day.
Getting fewer than the 5-6 cycles makes for a restless night, which can, in turn, lead to parasomnias.
Knowing how much sleep do I need is important, but unfortunately, most people will have some trouble falling asleep at some point in their lives. Luckily, there are ways to overcome such episodes, including keeping a sleep diary, using a sleep cycle app, or even undergoing a stress test.
Keeping a sleep diary is useful for understanding why you cannot fall asleep that easily. It is recommended to jot important things down both in the morning and at the end of the day, from the moment you acknowledge the problem up to at least 2 weeks.
Record in your diary whether you sleep on an improper mattress or in a room that’s too hot, whether you drink too much coffee before bed, or don’t exercise enough during the day. The aim is to identify any patterns.