Have you ever woken up in the morning feeling completely exhausted even after a full night’s sleep? More often than not, this isn’t because you need more sleep. It’s because you aren’t getting enough deep sleep. But what counts as deep sleep and how much should you get each night?
While you’re sleeping, you cycle through several different stages of sleep. One of these stages is deep sleep. Some scientists also call it slow-wave sleep, or non-REM stage 3 sleep.
The thing is, very few people get enough deep sleep. Technology, modern-day stresses, caffeine, and unhealthy eating patterns all decrease the amount of deep sleep you get and can result in chronic sleep deprivation.
Many wearable devices now track your sleep patterns, showing the amount and type of your sleep. While not fully reliable they can help indicate if you’re reaching the optimal level of 1.5 to 2 hours of deep sleep each night.
Getting enough deep sleep can make a huge difference in your life. Here are 7 of the most important benefits of deep sleep, followed by ways you can improve your chances of more restful sleep.
Scientists are still trying to figure out what each stage of sleep accomplishes for the immune system. So far, they have discovered that deep sleep plays an important role in the formation of immunological memory (3).
In other words, deep sleep helps your immune system develop a “memory” for bacteria and viruses you have been exposed to, which can help ensure you don’t get sick from the same pathogen again.
Research has found that the brain removes toxins during deep sleep (4). “It’s like a dishwasher,” explains Dr. Maiken Nedergaard, a professor of neurosurgery at the University of Rochester.
During the deep phases of sleep, the flow of cerebrospinal fluid (CSF) in the brain increases. CSF circulates nutrients and removes waste products or toxins from the brain.
Since the blood-brain barrier prevents the passage of most molecules, CSF is a vital component of the brain’s detoxification process because many of the compounds washed away via CSF are toxic to brain cells.
Beta-amyloid plaque, for example, is a sticky compound that accumulates in the brains of people with Alzheimer’s disease. Normally, CSF can help shuttle amyloid plaques out of the brain (5).
Just a single night of sleep deprivation can result in higher levels of beta-amyloid in the brain. Can you imagine what can happen with years of chronic sleep deprivation? Experts believe it may help explain the link between sleep disorders and Alzheimer’s disease (6).
When you are in deep sleep, your body undergoes countless processes to rejuvenate you on a cellular level. As such, deep sleep is often one of the biggest reasons why people either wake up feeling rested or exhausted (7).
Researchers have even found that chronic fatigue syndrome is associated with compromised deep sleep (8). That’s why you can get 8-10 hours of sleep and still feel completely exhausted if you didn’t have enough deep sleep.
Limited evidence suggests that deep sleep is involved in the production of a compound called brain-derived neurotrophic factor or BDNF (9). Several studies have found that BDNF may:
- Stimulate the production of new brain cells (10)
- Enhance learning and memory (11)
- Aid in the prevention of neurodegenerative disease (12)
Levels of BDNF tend to decline with age. So, deep sleep is even more important as we get older. If you’re under a great deal of stress and eat too many processed foods, that can also negatively impact your BDNF levels (13).
A bad night’s sleep can have a dramatic effect on your memory the next day, making it difficult to retain and recall key details (14). Research has also found that when you don’t get enough sleep it can impair long-term memory, decision making, and your ability to focus (15).
The connection between memory and sleep is well established. Scientists previously believed memory consolidation (forming and storing memories) happened during REM sleep—the dream stage of sleep (16).
It turns out, deep sleep is just as important for memory consolidation. Studies have found that increases in deep sleep can improve learning, information retention, and task performance (17).
Have you ever gone to bed while feeling stressed out? If you were able to get a good night’s sleep in, it’s likely you woke up feeling much better.
According to researchers from the University of California Berkeley, deep sleep reorganizes connections in the brain that result in reduced levels of stress and anxiety (18). Deep sleep provides an overall stabilizing effect on a person’s mood the next day.
On the contrary, they also found that a single restless night can raise anxiety levels by as much as 30%. So, if you ever find yourself stressed out or in an emotional slump, try improving the amount of deep sleep you get.
So, if you’re an athlete or involved in physical activity in any way, getting plenty of deep sleep could help boost your recovery process (23).
There are a variety of simple steps to improve sleep quality. These include reducing your exposure to blue light at night, sticking to a consistent sleep-wake routine, avoiding caffeine in the afternoon, and getting regular exercise. Studies suggest that exercise during the day can significantly increase the amount of deep sleep you get (24).
CBD Oil is also increasingly being looked at as a natural way to support restful sleep (25). To gain the full benefits of CBD Oil for sleep, seek out a broad spectrum oil with at least 25mg of CBD per serving and take it 30 minutes before bedtime.