Why We Sleep Summary

There are two main reasons we go to sleep:

• Circadian rhythm: Every living creature on the planet has some sort of sleep-wake cycle
• Sleep pressure: Every second you’re awake, a chemical called adenosine is compiling up in your brain. The concentration of this substance is increasing your desire to sleep

There are two stages of sleep:

• Rapid Eye Movement (REM): The brain activity is almost identical to when we’re awake. In this stage, we dream.
• Non Rapid Eye Movement (NREM): A dreamless sleep. During this stage, we’re calm, relaxed and the heart rate is slow and regular. There are four sub-stages of NREM Sleep: from 1 to 4, where 4 is the deepest form of sleep.

Each cycle lasts around 90 minutes with different NREM / REM ratios:

• Cycle 1: NREM (80%) -> REM (20%)
• Cycle 2: NREM (70%) -> REM (30%)
• Cycle 3: NREM (60%) -> REM (40%)
• Cycle 4: NREM (50%) -> REM (50%)
• Cycle 5: NREM (40%) -> REM (60%)

1. In order to have a better performance and better health, we should sleep 7-9 hours
2. Sleep is our superpower
3. If we prioritise sleep over work hours, our work hours could be more productive

This is one of my favourite books of all time, I have always known about the importance of sleep, but after reading this book, I started to take sleep really serious, making it the engine of my "productivity machine"

I think everyone should read it, it is definitely directed to everyone, since all of us has to conmute to bed every single day. Maybe, it is a great way to introduce yourself to health-related topics, the way the author explains the topic makes it accesible to all of us.

• Routinely sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer.

• Insufficient sleep is a key lifestyle factor determining whether or not you will develop Alzheimer’s disease.

• Inadequate sleep—even moderate reductions for just one week—disrupts blood sugar levels so profoundly that you would be classified as pre-diabetic.

• Short sleeping increases the likelihood of your coronary arteries becoming blocked and brittle, setting you on a path toward cardiovascular disease, stroke, and congestive heart failure.

• Sleep disruption further contributes to all major psychiatric conditions, including depression, anxiety, and suicidality.

• Too little sleep swells concentrations of a hormone that makes you feel hungry while suppressing a companion hormone that otherwise signals food satisfaction.

• The shorter your sleep, the shorter your life span.

• Sleep reforms the body’s metabolic state by fine-tuning the balance of insulin and circulating glucose.

• Human beings are in fact the only species that will deliberately deprive themselves of sleep without legitimate gain.

• Sleep further regulates our appetite, helping control body weight through healthy food selection rather than rash impulsivity. Plentiful sleep maintains a flourishing microbiome within your gut from which we know so much of our nutritional health begins. Despite being full, you still want to eat more. It’s a proven recipe for weight gain in sleep-deficient adults and children alike.

• Sleep enriches a diversity of functions, including our ability to learn, memorize, and make logical decisions and choices.

As per the reasearch done by various sleep scientist, sleep is essential for restoration of our physical wellness as well as emotional wellness.

In a layman terms, there are two type of sleep. First one being, deep sleep, which is very essential for our cordinated movement learning and restoration from fatigue. The other, one is REM (Rapid Eye Movement), in this sleep is important for our emotional wellbeing

Quality sleep makes us happier while crappy sleep will leave us in a mess in the morning and for the rest of the day

You know that many important decisions people take when they haven't sleep well the day before, and they regretted it. Some of those decisions could a life-changing decision.

Read the book and take a moment to appreciate sleeping 😊📖

1. Sleeping helps improve your focus the next day by flushing out all the memories of yesterday.
2. Quality of sleep is of utmost importance.
3. Sleeping has so many health benefits that even some medications can't help with!

Inorder to understand our sleep cycle,we first need to take into consideration the rising and setting of the sun! When the sun goes down and natural light disappears, our bodies begin to produce melatonin,a harmone that helps us fall asleep.In contrast ,when the sun rises and natural light increases ,our bodies produce more cortisol, which helps boost and balance our energy levels .