Mindset & Well-Being

The Science of Sleep for Personal Trainers and Wellness Professionals

It’s no secret that we live in a pretty stressful world. Electronics that emit blue light demand our attention professionally and personally, and human beings are spending less time exposed to natural sunlight.

There’s reason to believe this is leading to excess stress and, in turn, less sleep or poorer quality of sleep. Trainers, nutritionists, and health coaches are seeing more clients who are struggling to get the recommended seven to nine hours a night of sleep that they need to properly function. Fortunately, there are many solutions available to help people sleep, from proper sleep “hygiene” lifestyle practices to sleep supplements.

But what exactly is the nature of sleep? What is going on when we finally fall asleep, and what changes before we wake up? In this in-depth guide, we’ll be examining the science behind sleep, what lifestyle practices can help improve one’s ability to sleep, and what supplements out there actually work to promote sleep.

First, let’s explore what happens when we sleep.

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What Exactly Is Happening When We Sleep?

So, how exactly does sleep work? Well, to be fair, scientists aren’t 100 percent sure what is going on in our brains and bodies when we’re asleep.

There are two stages of sleep: non-rapid eye movement (NREM) and rapid eye movement (REM). Around 80 percent of the time we spend sleeping is during NREM. During this particular cycle, electrical patterns in the brain (sometimes referred to as “sleep spindles”) and slow delta waves occur. This is where humans experience their deepest sleep.

Without NREM sleep, humans experience many adverse health problems, which we will explore in more depth later on in this guide. The main issues we experience from a lack of NREM sleep include a lack of declarative memory forming and word processing, which are important in the process of storing memories in our brains.

NREM sleep is also where we release growth hormones into the body for the purposes of cell repair and reproduction.

The real mystery surrounding sleep involves REM sleep. We’re not entirely clear on what REM does for our brains and bodies. It has been found that REM sleep deprivation is not quite as severe as NREM deprivation.

What we do know about REM sleep is that it is the period in which we experience vivid dreams, although we can dream during NREM sleep. Dreams experienced in NREM sleep are more conceptual, while REM dreams tend to be more emotional. Some scientists believe that REM sleep allows us to process events or situations that we don’t regularly experience in order to “act” on them in a dream state. Others believe that dreams are a processing tool for dealing with trauma and unlearning memories. Either way, no one knows for sure, and very little about dream theory has been statistically proven.

During sleep (assuming one experiences a full seven to nine hours of sleep), one will cycle through five stages every ninety minutes or so. During these stages, one will experience between three and five dream periods each night.

The first stage of sleep involves a change in the electrical activity in one’s brain where drowsiness occurs. This involves a shift in and out of consciousness. This takes between one and seven minutes.

The second stage of sleep sees a slowing in brain activity and a lack of eye movement. This takes between ten and twenty-five minutes.

The third stage of sleep involves a drop in sleep spindles, followed by deep sleep. This takes between twenty and forty minutes.

The fourth stage of sleep is the deepest stage in which tall and slow delta waves occur. This takes between twenty and forty minutes.

The fifth stage of sleep or REM stage involves a “perking up” of the brain, and the electrical activity occurring within the brain becomes more and more similar to its awake state. This is the stage where most dreams occur. This takes between ten and sixty minutes.

The Health Benefits of Sleep

There are many benefits to getting a full night’s sleep. Some benefits are even a little surprising.

Heart Health

It’s been proven that strokes and heart attacks are much more likely to occur during early morning hours, which may be linked to how sleep interacts with human blood vessels. A lack of sleep or chronic insomnia has been linked with poor blood pressure and high cholesterol, which are major risks for heart disease as well as stroke. A good night’s rest can improve heart health.

Cancer Prevention

People who work late shifts tend to have a higher risk of developing several types of cancers, including colon and breast cancer. Researchers have reason to believe that exposure to light may reduce melatonin levels in the body. Melatonin, which is a hormone that regulates the human body’s sleep cycle, is believed to protect people from cancer due to its tumor-suppressing capabilities.

One can reap the rewards of cancer prevention with sleep by sleeping in a dark room and avoiding phones or tablets before bed.

Stress Reduction

A sleep-deficient body naturally goes into a state of stress. The body is in a state of alertness, which cranks up blood pressure and the production of unhealthy stress hormones in high amounts. High blood pressure can result in many different health problems, and having stress hormones present in the body can make it even more difficult to fall asleep—and so, insomnia becomes a vicious cycle.

To combat this, learning to meditate or use breathing exercises can help one get to sleep and reduce stress.

Inflammatory Issues

It’s truly surprising how many health problems can cause inflammation in the body. One such health problem is insomnia. A good night’s rest and regular sleep can reduce stress hormones that cause inflammation.

More Alert During the Day

Rest plays a big part in keeping you more energized during the day, and it also helps in promoting an engaged and active lifestyle. If you’re waking up feeling refreshed and don’t feel drowsy during any part of the day, you’re probably getting an excellent and high-quality amount of sleep.

Memory Improvements

Though it’s difficult to pinpoint why, since much about the nature of sleep is mysterious, sleep plays a big part in the process of memory consolidation. Memory consolidation is the brain’s way of making connections between events, feelings, and sensory input from the previous day. During sleep, the brain is hard at work compartmentalizing information in the brain that makes events and memories easier to recall.

Why We Need 7 to 8 Hours of Sleep Each Night

The generally accepted amount of sleep that an adult should get every night is between seven to eight (or possibly nine) hours. Infants require sixteen to eighteen hours, preschoolers require eleven to twelve hours, elementary school-aged children need at least ten hours, and teenagers need nine to ten hours.

We need that amount of time to efficiently grow new muscles, repair tissue throughout the body, synthesize hormones, and achieve an adequate amount of REM or “deep” sleep. We also need this amount of time to properly solidify and compartmentalize information we’ve taken in throughout the day via our senses. Though scientists don’t truly know exactly how or why we need that exact amount of sleep or the deeper processes that happen during sleep, it’s safe to say that it’s wholly necessary for optimal health.

The Health Risks of Sleep Deprivation

The Center for Disease Control and Prevention (CDC) has called sleep deprivation a public health “epidemic” due to the significant sleep deprivation statistics we’re seeing today.

There are many significant risks involved in not getting regular, undisturbed, restful sleep for up to nine hours per night.

One surprising health risk is one that has little to do with disease or illness. Sleep deprivation has been found to be a major factor in many accidents. The National Highway Traffic Safety Administration has estimated that fatigue as a result of exhaustion was a factor in 100,000 car crashes and 1,550 other crash-related deaths per year in the United States. 

It only makes sense that sleepiness can cause other accidents, such as injuries on the job.

Sleep deprivation can also increase one’s risk for diabetes, stroke, heart disease, heart attack, heart failure, irregular heartbeat, sleep apnea, stroke, and high blood pressure. Some researchers have even found that 90 percent of people who suffer from a chronic inability to sleep have some type of underlying health problem.

There is also reason to believe that sleep problems can cause issues with the human sex drive.

Common Sleep Hygiene Practices

Sleep hygiene refers to practices that one can implement in their lifestyle to improve their ability to sleep. It’s important to regularly commit to these practices to get the most of their sleep-inducing benefits.

Start Scheduling

Starting a sleep schedule can help your body get used to falling asleep and waking up at a regular time each night and day.

Reduce Stimulant Use

Caffeine and nicotine are stimulants that take some time to lose their effects on the brain and body. Reducing stimulant use a couple of hours before going to bed can help one experience better, more restful sleep. Reducing alcohol intake is also recommended. While a nightcap can certainly help you fall asleep, alcohol can disrupt your sleep cycle and brain processes as the alcohol is being processed out of your system.

Reduce Screen Time

Excessive exposure to blue light from the screens of tablets, cell phones, TVs and computers has been linked to the disruption of the natural sleep-wake cycle by suppressing the hormone melatonin. Suppressed melatonin functioning has been linked to numerous diseases. To counter this, try using tinted blue light-blocking glasses, reducing your screen exposure for one hour preceding your bedtime, sleeping in an entirely dark room, and adjusting your screen color to an orange hue in the evening.


A hard workout isn’t necessary to improve one’s sleep. As little as fifteen minutes of walking, biking, or other cardio exercises can have a significant effect on one’s sleep quality. It is recommended to avoid intensive or strenuous workouts just before bedtime.

Avoiding “Disruptive” Foods

Some people simply can’t sleep on an empty stomach, as it can cause some discomfort. For those who must have a snack before bed, it’s key to avoid a handful of sleep-disrupting foods.

Foods that are high in fat activate the body’s need to digest quickly, which can disrupt the sleep cycle. Similarly, heavy or spicy foods can lead to heartburn. This is because spicy foods can naturally trigger heartburn but also because our digestive systems slow down significantly when we sleep, so food is not broken down as quickly as it would if one were awake. . Citrus fruits and carbonated sodas can also trigger indigestion.

One should also cut off fluids two to three hours before going to sleep, as the need to urinate can disrupt the sleep cycle.

On the flip side, there are some foods that actually improve one’s ability to sleep and stay asleep. Tryptophan is a substance that promotes sleep and can be found in leafy greens, pumpkin seeds, peas, mushrooms, and broccoli.

Monitoring Naps

Naps have some serious benefits, from reduced fatigue to improved mood. There are some drawbacks, though. Sleep inertia, the state of cognitive impairment or “grogginess” that occurs after sleeping, tends to be more intense after a nap. While short naps don’t affect one’s regular nighttime sleep quality in most cases, prolonged or constant naps can lead to disruptions with one’s circadian rhythm.

The best way to avoid the downfalls of naps is to keep them short, approximately sixty to ninety minutes. Avoid napping multiple times per day. Also, take care to nap somewhere comfortable where sleep disruptions are less likely to occur to preserve the quality of the sleep you get while napping.

Common Sleep Aids

While there are many sedatives out there that can be prescribed for insomnia, there are some health risks associated with long-term use. In some cases, a sedative may not even be necessary. Three major natural sleep aids are melatonin, valerian root, and magnesium. Lavender has also been found to induce relaxation and, thus, improve one’s ability to fall asleep.


Melatonin is a naturally occurring hormone in the brain that lets the body know when it is time to go to sleep. It is produced by the pineal gland and has also been found in the gut. Known as the “sleep hormone,” melatonin at high levels can help human beings fall asleep quickly.

Still, melatonin cannot “force” you to sleep. It’s simply a hormone that notifies the body that it is nighttime and helps the body relax.

Melatonin supplements are quite safe, easy to find, and can be taken shortly before bed to help one fall asleep. They are also a great antioxidant with various other health benefits—they can improve eye health, reduce stomach ulcers, and ease heartburn.


Valerian Root

If you’ve ever smelled valerian root, you probably can’t forget it. While the plant itself has a rather unpleasant odor, the root of valerian has some pretty impressive health benefits.

Valerian root contains a substance called valerenic acid that affects the receptors for gamma-aminobutyric acid (GABA) in the human brain. From what science knows thus far, GABA can control anxiety and fear that is experienced when nerve cells are overstimulated. Thus, valerian root can work as an antianxiety drug or mild sedative. This, in turn, can help promote sleep.

Valerian root can be enjoyed in tea (it does not taste the same as how it smells), capsules, and tablets. 


An essential mineral, magnesium plays a major unsung role in overall health. It improves metabolic health, can regulate mood, reduce stress, improve heart health, and, of course, improve sleep.

Insomnia is often found to be the result of a magnesium deficiency. Like valerenic acid, magnesium maintains GABA levels. Magnesium can be taken as a supplement. It can also be found in a wide range of foods, including bananas, avocado, leafy vegetables, and some seafood.


Sweet and soothing lavender is found virtually all over the world. It has many different uses, one of which is as a sleep aid.

However, it’s worth noting that lavender does not act as a sleep aid in the way that melatonin or GABA-maintaining compounds do. The scent of lavender (aromatherapy) is believed to improve relaxation via the sense of smell. It is not a sedative and does not offer any significant changes to the brain that would impact sleep.

There have been a few studies to support the benefits of using lavender to relax. In one study, a group of patients who were given lavender to improve their ability to sleep saw 14 percent greater effects than the group without lavender. Even if the plant does not significantly improve one’s ability to sleep, it can be a good aid for clients who do not wish to consume a supplement or drug to reduce their insomnia.

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