Improving Sleep - Special Issue
A guide to Good Night's sleep
Do you wake up in the morning feeling refreshed and energized, or groggy and irritable? For a lot of individuals, the latter situation is a frequent occurrence. The average sleep time has come down to 7 hours from 9 hours in 1910. In fact more than 35% people sleep for less than recommended 7 hours. Getting an undisturbed night's sleep can significantly impact your state of mind the following day. However, habitual and restful sleep is equally crucial in the long term. As accumulating research indicates, regularly getting quality sleep is crucial for maintaining good health and overall well-being. Inadequate sleep can leave you feeling too fatigued to perform efficiently, exercise, or maintain a healthy diet. Over time, sleep deprivation can increase the risk of several chronic health conditions, such as obesity, diabetes, high blood pressure, and heart disease
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What is Sleep?
Sleep is something that everybody intuitively grasps. We know that we need to shut down and “power off” every night in order to function well during the day. Yet it’s hard to define exactly what sleep is.
The nerdy definition usually goes something like this:
Sleep is a reversible behavioural state of perceptual disengagement from and unresponsiveness to the environment.
Sleep is a state of unconsciousness from which a person can be aroused by stimuli.
In other words, it’s a time when our brains and bodies partially “disconnect” from what’s around us.
It’s kind of like what happens when you put your phone on airplane mode. Your phone still works, but it’s not getting any signals, so you can’t make calls, check your email, or scroll cute baby elephant videos on social media.
During some parts of sleep (particularly while we’re dreaming), our brain also “disconnects the wiring” from most of our skeletal muscles.
This means we become effectively and temporarily paralyzed, which prevents us from acting out our dreams. (It’s not a perfect system, as we’ll see when we take a look at things like sleep behavior disorders.)
But, unlike more profound forms of “disconnect” (like being unconscious, comatose, or under general anesthesia), we can be woken up from that disengaged state. When we wake up, we can “plug back in” to our surroundings. The “wiring” (i.e., nervous system connection) between our brain and skeletal muscles also comes back online.
This makes sleep a magical thing: We can temporarily immobilize and disconnect ourselves for several hours, and then — incredibly — return from that underworld.
Stages of Sleep
“Sleep” can be divided into two different categories: non-REM, or non-rapid eye movement that has four different stages and REM.
When we’re dozing off, teetering on the edge of waking and sleeping we enter the first stage of sleep.
In stage two, the body relaxes. Heart rate and breathing slows.
Stage three (and four) are known as “deep sleep.” They can be identified by delta waves in our brain (and also by being hard to wake up from!)
So far, all of these stages have been non-REM sleep.
Another stage, REM sleep, is unique. During this stage, our brain has levels of activity that are almost equal to when we’re awake. Our eyes move rapidly while closed.