What is sleep and sleep cycles?

What is sleep?

We all hear that sleep is important, but we rarely stop to think about what exactly happens when we lay down at night (or during the day). While it may look like we’re doing nothing when we’re in this state of rest, our brains and bodies are actually quite busy doing internal housekeeping. In fact, sleep affects everything from our mood to immune system and even our ability to create and store memories. While everyone’s sleep rhythm is unique and sleep patterns change throughout our lives, a good night’s rest is key to everyone for optimal health. Far from being outside of our control, there are actually plenty of things we can all do to give ourselves a higher chance of sleeping well.

What are sleep cycles?

Sleep actually occurs in cycles that last anywhere from 90 to 120 minutes. During this time we move through five stages of sleep. Non-rapid eye movement (NREM) sleep composes the first four stages which move us from a light sleep to a very deep one. The fifth and last stage, where most dreaming occurs, is called rapid eye movement (REM) sleep. During REM, our eyes begin to move quickly from side to side behind closed eyelids.

It’s typical for someone to enter the REM stage of sleep about 90 minutes after first falling asleep and going through the first four stages of NREM. The REM cycle usually lasts about ten minutes and will get progressively longer throughout the night. The length of the REM stage will also vary throughout our lifetimes: infants spend about 8o percent of their total sleep in this stage while adults spend 20 to 25 percent. The amount of time spent in the REM stage will then drop in people in their 60s.

Stages of sleep cycle

Each night, our bodies go through this five-stage cycle four to six times. Each of the sleep cycle stages plays an important role, which explains why you might not feel your best when there are sleep disturbances. Once you understand the benefits of each stage of sleep, you’ll see why it’s so important to keep a regular sleep schedule.

Here’s the beginner’s guide to the 5 stages of sleep:

  1. We’ve all been here: this is when we begin to lightly drift in and out of sleep. Our eyes move slowly and muscle activity slows down. It’s very easy to be roused awake during this time. Some people may also experience muscle movements followed by the sensation of falling. If you’re curious about trying sleep breathing techniques, this is the stage to try them.
  2. Light sleep continues in this stage. Here, our eyes stop moving, our heart rate begins to slow down and our body temperature starts to drop. Even our brain waves slow down with sudden bursts of oscillatory activity called “sleep spindles.” About half of our daily sleep is spent in this stage.
  3. Here we start entering deep sleep, where very slow delta waves start to appear interspersed with shorter, quicker waves. This is the stage where our body grows and repairs tissue, fortifies the immune system and builds bone and muscle. It’s also during this stage that a person may experience behaviors known as parasomnias such as sleep walking or talking out loud.
  4. Deep sleep continues in this stage and the body continues to replenish itself. Studies have shown that this is where the good stuff like saving your previous day’s experiences to your memory and the release of mood and energy regulating hormones occurs. Someone woken up at this stage may feel groggy and feel disoriented.
  5. The REM part of a sleep cycle is still a bit of a mystery. At this point, your brain starts sending signals to the brain’s cerebral cortex, the area responsible for good stuff like learning, thinking and organizing information. At the same time, other signals are sent to the spinal cord to shut down movement—this is to prevent you from doing things like kicking someone in your sleep thinking you’re kicking a ball.

    At this stage, there are even signals that appear to be random. It is believed that the brain’s cortex attempts to interpret and find meaning in these “random” signals thereby creating a story and a basis for our dreams. For the curious: observing rapid eye movement in other species can point to whether they can dream. This means that mammals, reptiles and some birds actually dream and explains why some dog owners observe their pets barking or pawing at something in their sleep.


Dreaming has fascinated people since the beginning of time. If you’ve ever thought, “I don’t dream when I sleep,” you’ll be surprised to learn that everyone does. Besides being super interesting, dreams can also reveal a lot about your sleep cycles. Since REM sleep and the ability to recall dreams are closely related, it means that the longer your REM cycle, the more intense your dreams will be.

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Dreaming has fascinated people since the beginning of time. If you’ve ever thought, “I don’t dream when I sleep,” you’ll be surprised to learn that everyone does. Besides being super interesting, dreams can also reveal a lot about your sleep cycles. Since REM sleep and the ability to recall dreams are closely related, it means that the longer your REM cycle, the more intense your dreams will be.



How sleep affects your health

Good sleep has a direct and positive impact on health. It can:
  • Improve memory
  • Help with inflammation
  • Boost creativity
  • Improve athletic performance
  • Promote healthy learning
  • Focus your attention
  • Help maintain a healthy weight
  • Lower stress
  • Balance your mood
  • Even live longer!

Sleeping well each night can help with anything from dark under-eye circles to being more present in your daily life.


How sleep affect growth

Human growth hormone, or HGH, is key contributor in helping kids grow. It’s absolutely crucial for building healthy bones, muscles and nerves. While HGH is released in small amount through the day, it’s released in its highest amounts during deep sleep. This means that a person’s growth can be impacted over the long-term if they don’t get a sufficient amount of rest each night. And, it’s not only kids that can be affected: hormones for adults that regulate weight are also released while the body is in rest mode.


How does sleep affect the brain?

The effect of sleep on the brain has been widely researched and cannot be stressed enough. Important brain functions can only occur while the body is sleeping and cannot be replicated while the body is awake. Sleep allows the brain to edit memories acquired from the previous day and to restore itself for the day ahead. Even one night of bad sleep can negatively impact a person’s ability to function to their full capacity at home, school, or in their community.

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Nectar Mattress


A full sleep cycle takes anywhere from 90 to 120 minutes. However, it is important to note that our bodies go through several of these cycles during our sleep. For this reason, it’s recommended that adults sleep 8-1o hours. Meanwhile, kids need 9-12 hours a night and infants even more than that to promote healthy growth.

Almost a third of adults have reported that they’re sleeping poorly. The most common disorders include:

Insomnia: Difficulty falling asleep or staying asleep even if someone feels they are tired. People with this condition are often dissatisfied with their sleep and can suffer from symptoms like fatigue and an inability to focus leading to poor performance the next day.

Sleep apnea: A disorder in which breathing is interrupted while sleeping. There are two causes: either a person’s airway is blocked or the muscles responsible for breathing aren’t getting the right signals from the brain. In either case, this stress on the body can cause high blood pressure, heart attack and even stroke.

Restless leg syndrome (RLS): This is a disorder in the central nervous system which can give people an itching or prickling feeling in their legs, often while laying in bed. This can cause people to feel a strong urge to move their legs to relieve these sensations. The nightly discomfort can lead to sleep deprivation.

REM behavior disorder (RBD): In the REM stage of sleep your mind is very active while your body is temporarily paralyzed to prevent your body from physically moving in response to dreams. In contrast, people with RBD retain the ability to physically move their bodies in response to what is happening in their dreams, which can lead to serious injuries.

Narcolepsy: People with this chronic sleep disorder can find themselves feeling excessively drowsy throughout the day, even falling asleep suddenly. These episodes of sleep are often brief, a few seconds or minutes, but can be disorienting as people are unable to remember what just happened.

Sleepwalking: This is a disorder more common in children although it can occur in adults where a person gets up and walks around while in a state of sleep. It is more likely to occur if someone is sleep deprived.

Sleep terrors: Someone suffering from this disorder might react to a sense of fear while sleeping and react by screaming or thrashing about in their sleep. Someone in the middle of a sleep terror can be difficult to wake up. When they do wake up, they may feel disoriented, be covered in sweat, or feel their heart racing.

Teeth grinding: Grinding or clenching one’s jaw during sleep can be a physical manifestation of feeling stressed or anxious. If left untreated, it can lead to the wear down and damaging of teeth, headaches and jaw pain.

There are plenty of sneaky ways that our sleep can be disturbed. Common reasons are having to get up to use the bathroom, drinking alcohol within four hours of going to bed, heartburn from dinner, pain from arthritis, having caffeine too late in the day, or stress. It can also be your room: use blackout curtains to ensure an optimal sleep environment, keep the temperature slightly cool around 65 degrees, abstain from blue-light exposure in electronics right before bed and make sure that your mattress isn’t pushing against your pressure points or letting you sink in too deeply.

Kleine-Levin Syndrome known as KLS or “sleeping beauty syndrome” is a rare sleep disorder. It is characterized by recurrent periods of excessive sleeping followed by behavioral and cognitive problems during waking hours. While the causes of KLS are unknown, it primarily strikes during teenage years with episodes ceasing with the onset of adulthood.

The top sleep disorders fall under the category of insomnia. Symptoms include difficulty falling asleep, staying asleep, waking up and not being able to fall back asleep, or waking up earlier than a person would like. While many people accept these conditions as something inevitable, the risk of doing so is high: studies have shown that people with insomnia can be prone to depression, have a lowered ability to focus and may be prone to accidents.

It’s awful to feel exhausted and lay in bed trying to sleep without success. In fact, the more you try the more difficult it can be to fall asleep. Many people with insomnia describe their condition as being chronically tired, but unable to sleep. In such cases, even if you feel that you aren’t particularly sleepy, you can encourage sleep by making sure your room provides a great sleeping environment.

There are many ways to try falling asleep fast. Some people have success by limiting their exposure to light before bed, meditating before sleep, listening to binaural beats, or taking a warm bath before bed. A good mattress can also support you in various ways by keeping you cool and providing the right amount of support. It’s also important to have cool and comfortable sheets as well as pillows that support your sleeping style.

If you have trouble sleeping, try developing a bedtime routine that you consistently keep each night. This could include doing something relaxing before bed like reading or writing in a journal. Just remember that the point is to avoid over-stimulating activities like watching action movies or checking emails on your phone.

If you’re bored in bed, it might be a good thing. Being calm and relaxed signals to your body that you’re ready to wind down. Just be sure not to overthink being bored which can stress you out and prevent sleep. Balance is key here: avoid electronics and try reading a book or making a list of things you want to accomplish the next day. This can help relieve your mind from worrying about the next day’s to-dos.