The Science of Sleep: How to Sleep Well


The argument about the quantity and quality of sleep for adults is never-ending. Should you go to bed before dark? Does a midday nap have a positive or negative effect on your personal effectiveness? Why can you feel tired even after eight-hour sleep? Let’s dig into the question of quality sleep and how to get it.

REM vs. Non-REM sleep: why sleep stages are important

A grown-up adult needs from 7 to 9 hours of sleep per day. There are two main types of sleep: Rapid Eye Movement (REM sleep) and Non-Rapid Eye Movement sleep (NREM sleep). It is crucial that you have enough of both for a full recovery. NREM sleep takes 75-80% of all sleep time, and this period is the most useful for the human body. During this time, the muscles get blood flow, the tissues regenerate, and useful hormones (for example, testosterone) replenish. The brain lymphatic system flushes out beta-amyloid metabolites, which accumulate in case of deficiency in NREM sleep and can lead to dementia or Alzheimer’s disease. During this stage of sleep, our brain sorts our memories and transfers them from short-term into long-term memory.

In the second stage, the brain generates dreams. While we watch our dreams, the brain structures our emotional memories and helps to memorize various skills, from switching on the coffee machine to driving a car.

What keeps us from having a good sleep

Apnea or stopping breathing while asleep can break the deep sleep and all important recovery processes related to it. The recurrent waking up and falling asleep during the night, caused by apnea, break the structure of sleep, which makes us feel tired even after sleeping full 7-8 hours.

Temporary deprivation can be another cause for breaking deep sleep, for example, if for several weeks you slept less than usual. In the short run, it can lead to decreased performance and cause mid-day slumps, irritability, and anxiety. In the long term, it can lead to not only psychological but also physical problems: obesity, the development of Type 2 diabetes, hypertension, and cardiovascular diseases.

Your sleep can be influenced even by the temperature in your bedroom, which is often overlooked. The lower the temperature around us, the easier it is to fall asleep and to shift from light sleep to deep sleep stage. Sleep psychologists consider 60-64°F as an optimal temperature for sleep.

What are good sleep hygiene practices?

The problems with sleep don’t pop up from anywhere, and it’s advisable to take preventive measures to avoid them.

  • Make a schedule and go to bed at the same time. It is boring, but it can help to avoid situations when you went to bed two hours earlier but couldn’t fall asleep.
  • Don’t drink alcohol for 4 hours and coffee for 6 hours before sleep. Tea and chocolate include caffeine, so you should also be careful with them.

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