Sleep is not just a period of physical rest; it is a vital biological process that keeps our brains and bodies functioning at their best. In his book Why We Sleep, researcher Matthew Walker unravels the secrets of sleep and offers a deep scientific perspective that helps us appreciate its true value and how to invest in it to improve health and quality of life.

Sleep affects every aspect of our lives, yet many healthcare systems neglect this element. During sleep:

• The immune system renews, increasing our ability to fight viruses and bacteria.
• Brain detoxification processes clear out toxins accumulated during wakefulness, protecting us from neurological decline.
• Growth and repair hormones are secreted, rebuilding tissues and strengthening muscles.
• Memories are consolidated and learning mechanisms are regulated, enhancing academic and professional performance.
• Hormonal balance related to appetite and metabolism is regulated, reducing risks of obesity and diabetes.

From this standpoint, sufficient sleep is not a luxury but an indispensable necessity for maintaining long-term physical and mental health.

A night's sleep typically involves about 4–5 cycles, each lasting around 90 minutes, divided into three main stages:

1. Light Sleep

   Muscles begin to relax, and breathing and blood pressure slow down. It serves as a gateway to deep sleep.

2. Deep Sleep

   Known as slow-wave sleep, the body increases secretion of repair hormones. During this stage, the brain detoxifies protein waste, and cells repair tired tissues.

3. Rapid Eye Movement (REM) Sleep (Dreaming)

   A phase of intense brain activity, showing electrical patterns similar to wakefulness, though the body experiences partial paralysis to prevent acting out dreams. Emotional memory, creativity, and problem-solving are enhanced here.

Each stage complements the others; missing any part disrupts overall sleep balance and affects both mental and physical health.

In many societies, lack of sleep is widespread due to work pressure, technology, and low awareness of its importance. Chronic sleep deprivation leads to:

• Weakened memory, concentration, and daily performance decline.
• Increased anxiety, depression, and mood disorders.
• High blood pressure and elevated risks of heart disease and stroke.
• Hormonal imbalances affecting satiety and appetite, contributing to weight gain.
• Slower wound healing, weakened immunity, and higher chances of chronic illness.

Studies show that people sleeping less than six hours a day face long-term health risks comparable to those caused by smoking or severe obesity.

1. Establish a Regular Sleep Routine

   Stick to consistent sleep and wake times to regulate your biological clock. Set a time to stop working at least one hour before bedtime.

2. Reduce Exposure to Blue Light

   Electronic screens emit blue-green light that decreases melatonin secretion, delaying sleepiness. Use blue light filters or avoid devices before bed.

3. Create an Ideal Sleep Environment

   Keep your bedroom dark, quiet, and slightly cool. Invest in pillows and mattresses that support your neck and spine.

4. Manage Food and Drink

   Avoid caffeine after midday and stimulant soft drinks. Limit heavy fats and proteins well before bedtime.

5. Practice Relaxation Techniques

   Meditation, deep breathing, and gentle yoga before bedtime activate your parasympathetic nervous system and prepare you for sleep.

6. Avoid Excessive Daytime Sleeping

   Short naps (20–30 minutes) can be beneficial, but long daytime sleeps disrupt night-time sleep cycles.

Good sleep starts with daily organization and routine. The "Second Brain" template on Notion assists you in:

• Fixing your sleep routine: Log sleep and wake times and receive reminders before bedtime.
• Tracking sleep quality: Enter your comfort ratings and wake-up stages to generate graphs showing your progress.
• Scheduling relaxation habits: Plan a few minutes of meditation or reading each evening in your recurring tasks.
• Monitoring influencing factors: Link your eating and drinking habits before bed to identify what improves or hinders your sleep.