Scientists agree that sleep is essential to health, and while stages 1 to 4 and REM sleep are all important, deep sleep is the most essential of all for feeling rested and staying healthy. The average healthy adult gets roughly 1 to 2 hours of deep sleep per 8 hours of nightly sleep.
REM is often considered the most important sleep stage, but light sleep is the first step to getting a healthy night's rest. It's part of the complete sleep cycle, and though it may sound like it won't yield restfulness, it's actually quite the opposite.
The most important sleep stage is Stage 3, Non-REM or, Delta (Slow Wave) Sleep, it takes up 25% of our total sleep cycle, and it's known as the 'deepest' period of sleep. It's in Stage 3 that sleep is at its most restorative, helping our bodies heal themselves and our minds rest.
All sleep is important, but REM sleep in particular plays an important role in dreaming, memory, emotional processing, and healthy brain development.
For healthy adults, spending 20-25% of your time asleep in the REM stage is a good goal. If you get 7-8 hours of sleep, around 90 minutes of that should be REM.
The takeaway.
Spending around 90 minutes in REM sleep each night is considered healthy for most adults, though it depends on the person.
Rapid eye movement (REM) sleep is the deepest stage of sleep. As the name suggests, the irises of your eyes move rapidly during this stage. It is the fourth stage of sleep. This happens approximately 90 minutes after falling asleep.
Scientists agree that sleep is essential to health, and while stages 1 to 4 and REM sleep are all important, deep sleep is the most essential of all for feeling rested and staying healthy.
Most adults, but not all, require 7 – 9 hours of sleep. Deep sleep must be a part of this nightly sleep. If you do not routinely get enough deep sleep, a number of issues can arise or be exacerbated including heart disease, a weakened immune system, an increased risk of stroke, and (for men) erectile dysfunction.
Waking up at the end of the cycle, when sleep is lightest, may be best to help the person wake feeling more rested and ready to start the day. An alarm going off when a person is in one of the deeper stages of sleep may lead to grogginess or difficulty waking up.
An average sleep cycle lasts about 90 minutes. Ideally, you need four to six cycles of sleep every 24 hours to feel fresh and rested. Each cycle contains four individual stages: three that form non-rapid eye movement (NREM) sleep and one rapid eye movement (REM) sleep.
Getting enough REM sleep is an essential part of keeping your brain and body healthy and optimizing daily performance. So, how much REM sleep do we need? On average, for most adults it's about 90 minutes per night.
Insomnia, undiagnosed sleep disorders and chronic sleep deprivation can result in a lack of rapid eye movement (REM) sleep, which can have a serious impact on your quality of life — and your health.
Focus on the Amount of Sleep You Get Overall Instead of Deep Sleep. Deep sleep should be about 10% to 15% of your overall sleep, but as everyone needs a different amount of sleep each night, the ideal amount of deep sleep can vary wildly from person to person.
Awakening During REM Sleep Results in Negative Mood and Self-Appraisal - American Academy of Sleep Medicine – Association for Sleep Clinicians and Researchers.
Multiple studies have shown that lack of slow wave sleep contributes to daytime grogginess and poor mood. Additionally, waking up during REM cycles interrupts our flow of aggregating memory. In order to make sure you wake up during light sleep, try and schedule your sleep in 90-minute multiples.
Dreaming sleep is a deep stage of sleep with intense brain activity in the forebrain and midbrain.
The third stage of non-REM sleep is the deepest sleep phase—it's the one that makes you feel well rested and energetic the next day. This stage of sleep is also when the body repairs and regrows tissues, builds bone and muscle and strengthens the immune system.
In your first sleep cycle light sleep often lasts between 10-30 minutes, and it gets longer during subsequent cycles. On average you'll go through 3-5 sleep cycles each night and 40-50% of that consists of light sleep. The average for WHOOP members is between 3.5 and 4 hours of light sleep per night.
So, do FitBits, Apple Watches and Oura Rings track sleep with accuracy? The answer is, not really. Particularly when it comes to sleep stages. These wearables measure movement very well and are great when used for tracking steps and exercise.
Under normal circumstances, you don't enter a REM sleep stage until you've been asleep for about 90 minutes. As the night goes on, REM stages get longer, especially in the second half of the night. While the first REM stage may last only a few minutes, later stages can last for around an hour.
Interview Highlights. What is hypersomnia: “Hypersomnia is when people sleep too much. When they wake up, even though they've slept ten, 12 hours, they don't feel rested. During the daytime, they also get sleepy or have small naps, and therefore hypersomnia lasts all 24 hours.
Taking a melatonin supplement can help increase deep sleep in a few ways. First, it can help to regulate your sleep cycle. This makes it easier for your body to fall into a deep sleep state. Second, melatonin can help to reduce stress and anxiety.