Why do we need sleep, anyways?

Why do we need sleep, anyways?

When you sit down to think about it, sleep has an aura of mystery, doesn’t it? Research indicates why we need sleep, for physiological reasons such as brain function, but what are the deeper-seated reasons sleep is so vital to our existence, how does it work, and what really happens during sleep that doesn’t happen while we’re awake?

Studies show the development of sleep is still in its theoretical stage. Modern research1 has found that sleep pushes beyond being restorative in nature but is intimately intertwined with a person’s overarching health. Going without enough sleep long-term can lead to health problems such as heart disease, depression, anxiety, and diabetes.

All of today’s mammals and birds engage in sleep, though different species have different rest needs. Even fish, insects, and reptiles have shown evidence of resting states. In humans, as well as most mammals, sleep is regulated by an internal clock, also known as the circadian rhythm.

We know that sleeping creates a vulnerable unconscious-like state, so again, creates curiosity behind its “why.” Some popular theories, behind why we evolved to need sleep, as outlined by Harvard’s Healthy Sleep website2 include:

  • Inactivity Theory – Organisms evolved to sleep at night to protect themselves from danger.
  • Energy Conservation Theory – Sleep reduces an organism’s energy needs at night when it’s not efficient to search for food.
  • Restorative Theories – Sleep allows an organism to repair and rejuvenate after the day’s activities, improving immunity, healing damage, promoting growth, and removing waste.
  • Brain Plasticity Theory – Sleep and the REM (rapid eye movement) cycle allows the brain to develop new connections, learn and process memories. Both REM and deep sleep (also known as non-REM sleep) are especially important for brain health. The rapid eye movements that occur during this phase are an indication of dreaming. Certain brain waves, called theta waves, are also produced during these critical phases of sleep.


So, what happens during sleep?

Fun fact: your brain does not turn off during sleep but rather, remains quite busy. Here is what your brain and body do while you sleep3:

  • Process and consolidate memories and learnings.
  • Cell repair and growth.
  • Removal of waste products and toxins that can lead to brain disorders later in life, such as Parkinson’s or Alzheimer’s.

There are also two types of sleep: sleep-wave sleep (SWS) and rapid eye movement (REM)4:

  • Sleep starts in the brain areas that produce SWS.
  • There are two groups of cells that are involved in prompting SWS.
  • When turned on, these cells trigger a loss of consciousness.
  • After SWS, REM sleep begins.
  • During REM, a dreamer’s brain becomes highly active while the body’s muscles are paralyzed, and their breathing and heart rate become erratic.
  • REM sleep’s purpose remains a quasi-mystery.

Get your rest. Adults need 7 to 9 hours of sleep per night. Doing this will promote a healthy immune system, prevent weight gain, give you a healthier heart, and even improve your mood.

Here’s some of our top tips for a good night’s sleep:4

  1. Have a routine – your body likes predictability.
  2. Avoid cell phones / tablets in bed – blue light is disruptive and can suppress melatonin.
  3. Take time to relax – pick up that book you’ve been meaning to read.
  4. Exercise –fall asleep faster and sleep better.
  5. Keep your room tranquil – set yourself up with a cool room with low noise and a comfortable bed.
  6. Take deep breaths – deep low breaths from your bellow can activate relaxation and lower your heart rate, blood pressure, and stress levels.

Sometimes, it’s the more you know. So, until next time, sleep well.

Share this post