概览

We spend one-third of our lives sleeping, but do you really know what sleep is? Is staying up late for work and catching up on sleep over the weekend useful? Why do we struggle to sleep in bed but feel sleepy during meetings?

In fact, you are not alone. About 30% to 40% of adults experience symptoms of sleep difficulties. Many people don’t focus on how long they should sleep but rather on how to have a high-quality sleep.

This article will systematically sort out the principles and methods of sleep, allowing you to fundamentally improve your sleep condition and enjoy a happier life!

Banks Can Go Bankrupt, and So Can Sleep

Difficulty focusing, sluggish reactions, memory loss, and emotional instability are all signs of chronic sleep debt. The best way to address this issue is to give yourself three to four weeks where you can sleep as much as you need each day. Over time, you’ll find your sleep duration naturally shortens. After about three weeks, your sleep patterns may stabilize at an ideal length.

Of course, this ideal scenario is almost impossible. For modern, busy individuals, carving out more sleep time is highly unrealistic. Balancing work, life, and personal interests leaves little room for adequate rest.

A common yet sad compromise is, “If I’m busy, I’ll just sleep less.” While unfortunate, it’s often unavoidable.

Basic Principles and Solution

Non-REM and REM Sleep

Let’s clarify two terms:

  • REM (Rapid Eye Movement): Also known as light sleep.
  • Non-REM: Also known as deep sleep.

After falling asleep, we quickly enter the first phase of deep sleep, the deepest sleep cycle of the night. It’s hard to wake someone during this phase, and even if you do, they’ll likely feel groggy.

About 90 minutes later, the first light sleep phase begins. Dreams in this phase are more logical and story-like, often reflecting personal experiences. In contrast, dreams during deep sleep tend to be abstract and less coherent.

Throughout the night, these two states alternate four to five times. As dawn approaches, light sleep phases become longer and shallower, leading to a natural awakening.

The key to better sleep lies in deepening that initial deep sleep phase. In our fast-paced world, ensuring overall sleep quality daily may be unrealistic. However, prioritizing quality during the first 90 minutes of sleep can make a difference, even if the total duration isn’t ideal.

The length of each sleep cycle varies by individual, but typically lasts about 100 minutes, including the 6–10 minutes it takes to fall asleep. While it’s unnecessary to strictly regulate your sleep duration, ensuring good sleep quality during the first 90 minutes is essential.

Interestingly, these first 90 minutes are also when the body produces the most growth hormones, crucial for physical growth, cell regeneration, and metabolism. They may even have anti-aging benefits, making them vital for health and youthful appearance.

The Body During Sleep

When awake, your core body temperature is 0.5–1°C higher than your surface temperature. Upon falling asleep, your core temperature drops while your surface temperature rises. The closer these temperatures get, the sleepier you feel—a phenomenon known as “sleepiness.”

For example, sleeping babies often have rosy cheeks and warm hands and feet because heat is dissipated through their extremities, signaling a drop in core temperature.

Sleep Solutions

  1. Bathing or Showering 90 Minutes Before BedCore temperature increases and then decreases afterward. Research shows that a 0.5°C rise in core temperature takes about 90 minutes to return to normal, helping you transition to a sleep state.
  2. Foot Baths if Time is LimitedSoaking your feet can quickly warm them, promoting blood circulation. The subsequent heat dissipation accelerates the drop in core temperature, facilitating sleep.
  3. Sleeping with Socks (Temporarily)Similar to foot baths, socks help warm your feet. Once warm, remove the socks to prevent heat buildup, which can interfere with core temperature decline. This principle also applies to hot water bottles and electric blankets—remove them once sufficiently warm.

A question for reflection: Why do you feel sleepy in air-conditioned meeting rooms?

Two Additional Sleep-Enhancing Methods

  1. Create a Fixed Sleep EnvironmentUse cues like calming music, rain sounds, or dim lighting to signal your brain that it’s time to sleep.
  2. Reduce Brain StimulationWatch boring movies or read dull books (low-rated ones work best). If that doesn’t work, try studying calculus—98% of people find it effective!

Sleep Danger Zones

It refers to the two hours before your usual bedtime. Our brain has a system that counteracts the increasing sleep pressure, constantly maintaining wakefulness. This system actively resists sleep.

Without this system, our brain wouldn’t be able to handle staying awake for 16 hours during the day. This theory explains why, if you need to wake up at 4:00 a.m. for a trip tomorrow morning and decide to sleep earlier tonight, you still find it hard to fall asleep. That’s because you’ve already touched your sleep danger zone.

The solution is that we don’t need to sleep earlier. Instead, we can shorten our sleep time a bit. If you really want to sleep earlier, you can advance some activities you usually do before bed, such as exercising or bathing, to help speed up the process of falling asleep.

Why Sleep Matters

Beyond producing growth hormones and fighting aging, sleep:

  1. Consolidates Memory

Studying or reading before bed helps you retain information better the next day. Use this to your advantage when preparing for exams.

  1. Regulates Hormones

Lack of sleep increases ghrelin, the hunger hormone, leading to overeating and potential weight gain.

  1. Clears Brain Waste

The brain floats in cerebrospinal fluid, which is replaced four times daily. Sleep facilitates waste removal. Chronic sleep deprivation can lead to waste buildup, impairing memory and potentially contributing to conditions like Alzheimer’s disease.

Mastering your sleep means mastering your life.