Although the reason is obvious on why we sleep, but the real truth is that there is very little knowledge explaining as to why we fall asleep and why we wake up at particular times?
Also why it is sometimes that we can wake up feeling refreshed and other days just feeling so annoyed and drowsy?
So before we start looking at the correct times to sleep we should take a look at some of the science behind sleeping. Feeling tired and not feeling sleepy is primary down to two different chemicals: Acetylcholine and adenosine. Acetylcholine is responsible for keeping us awake, whereas adenosine has the opposite effect making us feel sleepy.
These two chemical are constantly in a 'battle' with each other; adenosine builds up when we are awake and when we sleep acetylcholine take its turn to overcome the adenosine which will eventually have us waking up. Other chemicals which are involved in making us feel sleepy and then making us wake up are cortisol (an awake hormone) and melatonin (sleepy hormones)
The Chemistry of sleep
How long should I sleep?
For an adult, between seven and eight hours of sleep is needed; However, sleeping for too long and not getting enough sleep can both come with their own medical problems.
Not getting enough sleep can have serious effects on our brains ability to function properly. If you have ever pulled an all nighter you may have felt groggy, grumpy and rough. Chronic poor and restricted sleep for years and are known to be associated with the development of illness (Dr Simon Kyle)
What is the longest time a person has gone without sleep?
The world record for the longest time without sleep goes to Randy Gardner; in 1964, Gardner, a 17-year-old stayed awake for 264.4 hours (11 days 24 minutes). There were no real problems present after this; however, he did suffer from headaches and his overall daily routine was slowed.
I am sure you may have had an idea that lack of sleep may cause problems. But what about too much sleep?
Sleeping for too long can also be related to medical problems most commonly known for an increased risk of diabetes and also problems associated with heart disease (Huffingtonpost).
In a 2014 study of adult twins, researchers found that long sleep duration increased a person's risk of depression symptoms.
What time should I go to sleep?
When we finally hit the pillow after a long hard working day; we start our sleeping cycles.
Eugene Aserinsky and Nathaniel Kleitman, researchers at the university of Chicago, attached volunteers to a newly invented EEG machine; they found out that when we sleep we go through a series of different cycles which last for around 90 to 110 minutes. When we enter into one of the cycles we almost seem to be paralyzed, with the eyes being the only part of the body that moves; this is where the name 'Rapid eye movement' (R.E.M sleep) comes from. However, this alternates with non-REM sleep; when we wake up during these cycles we feel horrible; so to help us wake up feeling refreshed we need to wake up between cycles.
What time should we go to sleep?
Well fortunately there are a few apps and websites that calculate this and give you an estimate on the best time to sleep.
The best of these is the sleep calculator
The Sleep Calculator works on a 90 minute sleep cycle and calculates the perfect time between these cycles for you to get up feeling refreshed. On average, a person ought to experience 5 or 6 of these sleep cycles a night to wake up feeling refreshed and energized.