The Science Behind a Good Night’s Sleep


Over the last few decades, sleep scientists have learned and revealed quite a lot of information about why humans engage in the act of sleeping, what our brain activity levels are like when we are in this state, and what the physiological patterns of sleeping are.

Prior to this knowledge, we used to believe that sleeping was a passive activity that we engaged in to fight off fatigue and as such, our body and brains remained dormant throughout the duration of the state.

However, this is not the case according to Mark Wu, a John Hopkins neurologist, who states that during our sleep state, our brains are actually engaged in numerous activities that are necessary for life, which in turn, are closely linked to our quality of life.

Many scientists have studied the processes that our brains go through during sleep and how they impact our physical and mental well-being and this is what science says about getting a good night’s sleep.

What Is Happening in the Brain During Sleep?

Proper sleep recharges our brain the way that good food rejuvenates our bodies.

According to Diana L. Walcutt, our brains go through five different stages when we sleep. During these stages, our brains produce two different types of sleep, one which is a slow-wave sleep (deep sleep) and one which is a rapid sleep (REM) that is characterized by dreaming.

These various stages are important because different brain activities occur within them, which allows us to store old memories, make new connections, and eliminate clutter that we no longer need.

The five stages are as follows.

STAGE ONE: This is characterized by light sleep and is the stage that you want to be woken up from as it has the least going on with it. In this stage, we drift off through Alpha and Theta, two periods of dreaminess that are akin to daydreaming.

STAGE TWO: The second stage lasts about twenty minutes and is characterized by the brain producing short periods of rhythmic brain wave activity that are rapid in nature. These are called Sleep Spindles. Your body temperature will also begin to drop and your heart rate will slow.

STAGE THREE: The third stage is characterized by deep and slow brain waves also called Delta Waves. During this period, we transition from a light sleep into a deep sleep.

STAGE FOUR: During stage four, we are in a deep sleep that lasts for about thirty minutes. This stage can be characterized by sleepwalking and bed wetting.

STAGE FIVE: During stage five is when we experience rapid eye movement or REM sleep. This stage is characterized by very active brains and very relaxed and paralyzed muscles as well as dreaming. REM sleep starts at about ninety minutes into your sleep state and paralyzes you so that you cannot harm yourself in an attempt to act out on your dreams.

An individual will not progress through all of these stages in a linear sequence as one will go through stage one, two, three, and four and then proceed to repeat stage two and three again before moving into stage five. Once our REM sleep is over, we proceed back to stage two and cycle through these stages four to five times in one night.

So Why Do We Sleep & Why Is It Important?

Sleep is one of the more underrated pillars of health in our modern society.

Scientists believe that sleep is how our bodies restore itself, processes the day’s events, and files away our memories.  Getting enough sleep is important as sleep deprivation or a lack of sleep, leads to severe problems related to heart disease, depression, and hypertension as well as cardiovascular diseases, obesity, and negative impacts on our decision making, motor skills, and ability to cope and deal with stress.

According to a study published in the New York Times during our sleep stages, the connections called synapses, which are the connections between the neurons, actually shrink down. The connections which are the weakest out of them all are pruned and this is how we “forget” experiences that are no longer beneficial or relevant to our lives.

How Much Sleep Is Enough Sleep?

A person’s age dictates the amount of sleep required.

Although the optimum amount of sleep quoted by the US National Sleep Foundation is seven to nine hours for adults and eight to ten hours for teenagers, it can vary downward or upwards and is impacted by genes, age, and lifestyle.

However, what is clear is that younger children require more sleep, with newborns needing around seventeen hours a day. Some individuals can survive on less sleep and too much sleep can be a bad thing. However, getting less than seven hours of sleep has shown some negative impacts on health for the majority of the world’s population.

We Have Built-In Sleep Control Systems

Fighting against sleep is like going against the tide: we rarely if ever win.

There are two systems that regulate our sleep, the first being our circadian rhythms and the second being our sleep drive. Our circadian rhythms are controlled by our brains and is what we know as our biological clock. This biological clock responds to light cues and ramps up melatonin production at night, which is the natural hormone that makes us sleepy. This production of melatonin turns off when we respond to the sunrise in the morning.

Our sleep drive, on the other hand, is what makes us crave sleep. As our day progresses, our desire for sleep builds and this is why people can fall asleep during dangerous situations such as driving.

When one is exhausted, the body will push for micro sleep episodes, where you doze off for a few seconds, resulting in some serious side effects depending on your environment.

How to Get a Perfect Night’s Sleep According to Sleep Scientists

There are habits that you can practice to improve the quality of your sleep.

We’ve all experienced that dreadful day when we just didn’t sleep well the night before, and most of us may have no idea what we’ve done wrong. According to the Irish Examiner, science has finally managed to break down exactly what goes into getting the perfect night’s sleep, all night, every night. If you can follow these rules, you should be able to wake up every morning with enough energy to face the day.

Duration: You may have heard the age-old quote of 8 hours of sleep every night. Any less and you’re tired, any more, and you’re a lazy teenager. In reality, this number should be 7-9 hours, as everyone has different needs and some may need that extra bit of time in order to be at their best.

Efficiency: How long you sleep vs. how long you actually spend in bed can greatly affect your energy levels. Keep track of how long it takes you to initially fall asleep, as well as any lengths of time you spend lying awake at night because something woke you up unexpectedly. This can also be quantified as a number by totaling up the time you spent asleep and expressing it as a percentage. For example, someone who is in bed for 8 hours but only sleeps for 4 would say they have a 50% efficiency when sleeping.

Wake vs. Rise: when you wake up in the morning, keep an eye on how long it takes you to actually rise out of bed. Researchers have found that lying awake in bed for more than an hour in the morning will actually work against you. If you are trying to sleep longer because something woke you up unexpectedly, it may be better for you to simply get up if falling asleep again is taking too long.

Environment: Your environment not only affects initially falling asleep, but also affects you while you sleep. Ideally, the room temperature should be at 22 degrees Celsius with minimal light and no noises over 40 decibels.

Before Bed Routine: make sure that you have nothing stirring around inside your head before heading to bed. Finish any and all activities that don’t involve simply relaxing at least 2 hours before sleeping. For coffee and tea drinkers, make sure you aren’t consuming any caffeine within 6 hours of going to bed.

Disturbances: Sometimes disturbances are out of your control, but keeping them to a minimum can really make a difference. Take into account things like diagnosed sleeping problems, medicines or alcohol used as a sleep aid, and even a partner with their own sleep problems.

Also check out a previous article we have written on the seven commandments of a good night’s sleep here.