The Science Behind Healthy Sleep

Guest Post by Ben Hannson

Sleep is just as necessary to living as eating. Studies have shown that sleep-deprived rats die within two to three weeks—the same amount of time it takes them to starve to death. In 1965, a 16-year-old boy forced himself to stay awake for more than eleven days. By the end of that time, he failed to do simple math equations, his speech was slurred, his eyes could not focus, and he lacked any discernible concentration.

The bottom line: Getting a healthy amount of sleep is imperative if you want to be a happy, healthy, well-functioning person. Sleep deprivation makes us cranky, tired, and unable to do simple tasks or regulate our emotions. It can even lead to full-blown psychosis.

But have you ever wondered why we need to sleep? Or what happens during the one-third of our lives that we spend asleep?

The Whys

Truth is, scientists are unclear as to exactly why sleep is such a critical part of human existence. Theories abound. That sleep restores energy in the brain. Or that it helps the brain cells clear toxic waste. Or that it assists in neuroplasticity and connectivity, which in turn enhance learning and memory. The only solid fact is that sleep is crucial to life.

Though the brain seems to benefit most from sleep, so does the body. The biggest benefit of sleep is that it strengthens our immune system. Without proper rest, we’re vulnerable to depression, high blood pressure, heart disease, weight gain, stroke, and diabetes. These are all good reasons to make sure we’re getting the recommended seven to eight hours a night of shut-eye!

The How

Two main functions trigger sleep and wakefulness in humans: Circadian rhythms and sleep drive.

The first is basically your brain’s biological clock responding to light. At night, darkness signals your brain to produce more melatonin, which makes you able to sleep. As light reemerges, the brain shuts off melatonin production and you wake up.

The other, sleep drive, is like hunger but for sleep. Your craving for sleep builds throughout the day until that point where it becomes clear you need to go to bed. Although there’s no built-in mechanism to force us to eat, our body can and does force us to sleep eventually, no matter how hard we try to stay awake. Sleep drive simply won’t quit until we get some rest.

So what exactly happens when you sleep?

Our brains cycle between two different types of sleep four to five times a night. These are known as non-REM (rapid eye movement) and REM sleep.

Non-REM sleep makes up the majority of our time in bed and represents the deepest sleep. During this time, our brain waves form “sleep spindles” and high, slow waves. Non-REM sleep helps the formation of memories and is responsible for cell reproduction and repair.  

Non-REM begins the sleep cycle, and is composed or four stages. The first lasts one to seven minutes and is characterized by feeling drowsy. During stage two, brain activity slows further and we fall into a light sleep. Our eyes stop moving, but we still wake easily. This stage lasts ten to twenty-five minutes. The next thirty to forty minutes are spent in stage three. This is a moderate sleep where waking becomes more difficult.  Finally, we reach stage four sleep. This lasts anywhere between twenty to forty minutes and is the deepest sleep we experience. Our muscles all relax and we may even snore.

REM sleep is the fifth stage, where our brains become more active again and most dreams happen. Our eyes move back and forth and we’re unable to move your muscles.

This five-part cycle then repeats itself several times throughout the night. In each successive cycle, we spend less time in each of the non-REM cycles and more time in REM sleep. Dream on!

Tips for Getting Enough Rest

Now that we’ve established why sleep is so important to our brains and bodies as well as what happens during a typical night, it’s time to make getting the proper amount of rest a priority. So make sure your room is primed for sleep by eliminating excess light and noise, practice self-care to overcome anxiety that can cause insomnia, and consider using a heavy blanket to encourage faster and deeper sleep. You’ll be amazed at how much good eight hours of solid rest will do for your mind and body.