When determining whether we’re getting enough sleep, we often focus on the overall duration of our sleep. However, there is an important factor some of us forget to take into account – sleep cycles. Composed of four different stages, sleep cycles determine both the sleep quantity and sleep quality we’re getting. So, if you’ve ever wondered: “what are sleep cycles and why do they matter?”, our article will help guide you through the different stages of a sleep cycle and explain all the important processes that occur in our body during each stage.
Apart from providing a detailed explanation for every stage, we’ll also go over the importance of getting enough sleep and share some of our best tips to ensure that your sleep cycles are optimized.
Without further ado, it’s time to delve into some of the reasons why it’s important to get quality sleep every night.
The Importance of Getting Enough Sleep
Before we move on to discussing what sleep cycles are and how they’re divided, let’s explore some of the reasons why getting quality sleep every night matters.
Helps With Concentration and Problem-Solving
Regardless of how you spend your days, chances are your job or studies demand you to remain concentrated for long stretches of time and to problem-solve on a regular basis. It turns out that getting enough sleep every night is one of the best ways to optimize your brain function. Sleep deprivation has been linked to various side effects that hinder our overall productivity levels, so if you’ve found yourself struggling with work or school recently, take a closer look at your sleeping schedule because it might be to blame.
Unsurprisingly, getting plenty of rest every night also helps with your job and school performance, so think again the next time you feel like you want to pull an all-nighter to cram for an exam.
As we will later explore, sleep also has an imperative function in memory retention, which is another crucial aspect of your performance.
Helps With Disease Prevention
Many fascinating discoveries in the field of sleep science have confirmed what we know already – adequate sleep has been associated with a lower risk of developing cardiovascular diseases, and it lowers your overall all-cause mortality.
So, if you want to lower your chances of suffering from high blood pressure and heart disease, you should aim to sleep at least seven hours per night.
Helps With Weight Regulation
One of the first tips we hear regarding maintaining a healthy weight is to sleep more. But this isn’t just a tip gym bros throw around – having a proper sleeping schedule helps regulate your appetite, maintain a healthy hormonal level, and keep your metabolism healthy, all aspects which influence weight maintenance.
Apart from having a direct impact on our body, a good sleeping schedule also gives us energy and helps motivate us to hit the gym more often, which is crucial for our overall health.
Improves Your Overall Quality of Life
We could go on and on about the importance of getting a sufficient amount of sleep every night and all the benefits that it entails. However, we will leave you with this fascinating find – quality sleep has been associated with greater life satisfaction in university students. It’s incredible the number of benefits you could enjoy by making one small change in your habits and regulating your sleeping schedule.
Now that we’ve gone over some of the reasons why getting enough sleep is crucial, let’s get to the gist of today’s topic and define what sleep cycles really are.
What Are Sleep Cycles?
As you know, all of us have different sleeping schedules. Some people require more sleep per night, like athletes or those who work physically demanding jobs, while others can get away with sleeping fewer hours due to their genetic makeup and similar factors. Well, sleep cycles work in a similar way – each person goes through several different sleep cycles per night until they eventually wake up. Most of us experience anywhere from four to six sleep cycles every night. Longer naps usually consist of one sleeping cycle, while shorter naps only allow us to enter one or two stages of the sleep cycle.
Speaking of, there are a total of four different sleep stages: the first three comprise non-REM sleep, while the last one is what we consider to be the REM sleeping stage where many important functions are executed.
You might wonder how scientists have made this conclusion. Well, to determine how many different sleeping stages there are and exactly what happens during each stage, scientists have analyzed the brain’s activity during sleep. Each stage has a distinctive brain activity pattern from which they were able to infer all the important information. To help you get a clear understanding of what the stages consist of, we will go over each stage independently and explain its duration, the important bodily changes that occur during it, as well as how our brain reacts to it.
The Different Stages of a Sleep Cycle
The first stage of the sleeping cycle is a part of the non-REM group of stages and it’s often referred to as light stage sleep. As you can infer from its name, it’s an in-between stage of not being fully asleep but also not quite awake. This is the shortest stage out of all, lasting on average five to ten minutes. Our sleep is pretty light during this stage, so this is when we’re most prone to being awakened by our family members, our pets, or any random noise we might be subjected to.
While the body isn’t fully relaxed during this stage, our brain activities do start to slow down gradually. Our heartbeat, breathing, and our eye movements also slow down.
You might’ve heard of the term power nap – they’re naps that are designed to be no longer than 20 minutes long and are meant to give you a boost in energy and concentration. Power naps rarely leave the first stage of sleep, so you never go into deep sleep. This is why they’re an incredible energy booster – they’re meant to give you all the benefits of sleeping without feeling drowsy and cranky at the end of it.
An interesting phenomenon we experience during this stage is the so-called hypnic jerk caused by various muscle contractions. This is the sensation we sometimes feel before falling asleep as if we’re falling down a cliff or a flight of stairs. While it can be scary and sudden, it’s nothing to be worried about.
If we’re not woken up during this stage, we move onto the second stage of non-REM sleep.
The second stage of non-REM sleep is characterized by sudden spikes in the brain waves, which is a change from the pattern that can be witnessed during the first stage of non-REM sleep. These spikes help prevent us from being suddenly woken up by any noise or change of light we might encounter. Generally, our brain activity is slowed down during the second stage and our brain starts to facilitate the process of memory retention and sensory processing. We start to shift from light sleep to deeper sleep as our body prepares to enter the third stage of non-REM sleep.
When it comes to other processes in the body, our breathing and heart rate are even slower, our eye movements stop, and we experience a drop in temperature. During this stage, our body becomes even more relaxed, but we do experience some muscle contractions.
The second stage of sleep can last anywhere from ten to twenty-five minutes, depending on the sleep cycle. It’s interesting to note that we spend the majority of our night in stage two of non-REM sleep.
During the third and final stage of non-REM sleep, our breathing, heart rate, and brain waves slow down even further. At this point, we have officially entered the deep stage of sleep, so it’s significantly harder for any external stimuli to wake us up.
Our muscles completely relax, so this stage has a crucial role in muscle building. It’s also responsible for storing memories, boosting our immune system, and general recovery. Deep sleep is also incredibly important for our mental health, problem-solving, and creativity, so this stage is one of the most important stages for our overall health.
It’s important to note that waking up during this stage isn’t quite desirable since we tend to be irritable and tired. If you think you’ve experienced this yourself, it might be a good idea to download a sleep cycle tracking app that allows you to set an alarm based on your sleep cycles, ensuring that you don’t wake up in the middle of one and experience some of the negative side-effects associated with it.
The third stage usually lasts from 20 to 40 minutes per sleep cycle.
The last stage of a sleep cycle, also called the REM phase, is still being studied. What we do know about this stage is that it’s when we experience dreams and our body goes through various different changes, such as an increase in blood pressure, breathing, and heart rate – essentially the total opposite of the first couple of stages. It’s interesting to note that while the above-mentioned processes pick up in speed, our muscles remain completely paralyzed during this stage. While we can dream during the other stages, it’s less common to do so, and the dreams we have during the REM stage are significantly more vivid than the dreams we have during the other stages.
This stage gets its name from the rapid eye movement that occurs during it. If you’ve ever watched someone sleep and noticed that their eyes move around a lot, it’s likely that they were dreaming during the REM stage.
The brain activity during REM also increases, which could be attributed to the fact that we often dream during this stage. This stage is crucial for memory retention, filtering the memories we’ve experienced, and other cognitive functions.
Babies and children spend the most amount of time in the REM stage. As we grow older, the duration of the REM stage decreases.
The duration of the REM stage depends on the sleep cycle. During the first couple of sleep cycles in the night, the duration of the REM stage is very brief and lasts only for a couple of minutes. As time goes on, the REM stage increases in duration. We spend approximately 25% of our sleep in the REM stage every night.
What Affects Sleep Stages?
We briefly mentioned that the duration of our REM stage decreases as we get older. Age plays a crucial part in determining the duration of our sleep stages and our overall sleep cycle. Newborns spend the majority of their night in REM sleep, while the percentage for elders is significantly lower.
Another factor that can significantly impact our sleep cycle is the presence of any sleep disorders. Some disorders that cause us to wake up in the middle of the night can be detrimental to our sleep cycles, such as restless leg syndrome.
Tips for Improving Your Sleep
We discussed the different sleep stages and what bodily and cognitive processes occur during them, so now it’s time to share some of our best tips for improving your sleeping pattern and enjoying uninterrupted deep sleep every night.
One of the best ways to ensure that you’re spending as much time as possible in deep sleep is to include a couple of higher intensity workout sessions per week. They don’t have to be incredibly intense and sweaty, but anything that gets your heart rate up is bound to have a positive effect on your sleep. You will fall asleep faster and enjoy deep, restorative sleep which will have a great effect on your physique and overall health. With that said, make sure you schedule your workouts earlier in the day because exercising in the evenings might hinder your ability to fall asleep at night.
Limit Your Caffeine and Alcohol Consumption
Alcohol and caffeine are some of the greatest enemies to a healthy sleep cycle. Consuming large amounts of caffeine and alcohol at night can be detrimental to your sleeping hygiene since these substances keep you up and can lead to a shorter REM stage. We know by now how important this stage is for memory retention and other cognitive processes, so if you’ve noticed that alcohol and caffeine have a negative impact on your sleeping schedule, limit your consumption and make sure you don’t consume them too close to bed.
Have a Consistent Sleeping Schedule
Last but not least, one of the easiest ways to improve your sleep cycles is to have a consistent sleeping schedule. This entails going to bed and waking up at approximately the same time every night. While it might be hard at first, doing so will significantly improve your overall sleep because our bodies love routines.
Install a Sleep Cycle Tracking App
One of the easiest ways to track how much deep, quality sleep you’re getting is by installing a sleep cycle tracking app. Not only will this show you exactly how much sleep you’re getting every night, but it will also provide a detailed analysis of your sleeping patterns. Most sleep cycle tracking apps also come with some interesting additional features, such as free meditation guides which can help you fall asleep faster.
Why Are the Cycles of Sleep Important?
Many major processes in the body occur during the sleep cycle, such as memory retention, muscle building, and overall healing. Spending time in deep sleep every night is crucial for every aspect of our health.
Which Sleep Cycle Is Most Important?
Every sleep cycle is important in its own way. Every stage is responsible for regulating different aspects of our body and brain and each one contributes to our overall health.
How Many Hours of REM Sleep Do You Need?
The amount of time you should ideally spend on REM sleep every night is around 25% of your overall sleep.
We go through several different sleep cycles every night. The duration of the sleep cycle varies from person to person, but the duration of each stage is approximately the same for all of us. There are a total of four different sleep stages: three non-REM stages and a REM stage.
The first stage of sleep is when we’re in the in-between stage and we experience light sleep. Our body isn’t fully relaxed, but our breathing and heart rate start to slow down. This continues during the second stage of sleep, where we’re much harder to wake up. We’ve officially entered deep sleep with the third stage, which is crucial for building our immunity, helping us become more creative, and problem-solving. The last stage of sleep, also known as the REM stage, is when we dream, filter through, and store our memories. We spend approximately 25% of our total sleep in the REM stage and this percentage decreases as we get older.
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