All about deep sleep
An introduction to deep sleep
You may know that adults need an average of seven to nine hours of sleep every night. While the amount of time you sleep is important, the quality of your sleep matters too.
Your body moves through different stages of sleep each night, and you cycle through them approximately every 90 minutes. The first three stages of the sleep process are classified as non-REM (non-Rapid Eye Movement) sleep, and the fourth and final stage is REM (Rapid Eye Movement) sleep.
Non-REM sleep (Stages 1-3): The first two stages of non-REM sleep are lighter phases of sleep where you can be easily awakened. The third stage is deep sleep, and this is a critical stage of sleep that has important benefits. The average adult needs to spend approximately one to two hours in Stage 3 deep sleep each night to feel refreshed and healthy.
REM sleep (Stage 4): Your brain is very active in this stage, and this is the period of sleep in which you experience dreaming. Once this stage is complete, the sleep cycle begins again and repeats throughout the night.
Features, importance, and function of deep sleep
Deep sleep is necessary for you to feel refreshed when you wake up in the morning. It is associated with the slowest brain waves during sleep, which is why it is commonly referred to as low-wave sleep. Eye movement and muscle activity stop, and it is difficult to be awakened during deep sleep. It is during this stage that memories are consolidated, and it is a restorative period for your brain and body.
During deep sleep, your brain processes all of the new information you encountered during the day. In a process known as sleep-dependent memory processing, it takes all of this information and converts it into storage in short-term and long-term memories. Deep sleep is also important because it is during this stage that the pituitary gland in your brain increases its secretion of growth hormone. This is needed for overall growth and development, cell regeneration, muscle and tissue repair, and strengthening of the immune system.
Overall, the main function of deep sleep is to give your brain a rest and time to restore itself from being active during the day. If you are aroused from a deep sleep, you’ll likely feel quite groggy, and mental performance can be impaired for up to 30 minutes afterwards.
Sleep disorders during deep sleep
The non-REM deep sleep stage is associated with several disruptive sleep-related disorders, or parasomnias. These can involve both physical and verbal activity, such as sleepwalking, night terrors, and sleep eating. In most of these situations, you are not fully awake or aware of what is happening and would likely be unresponsive to others if they attempted to interact with you. In general, individuals who suffer from parasomnias don’t remember many of the details, if any, of the event the next day.
It’s best to speak with a healthcare provider if you suffer from any sleep-related disorder. However, many parasomnias can be successfully managed without medication and by following the tips below to improve the overall quality of your sleep.
How to get more deep sleep
Factors that can increase deep sleep periods
If you hit the sheets too late at night on a regular basis, you may not be giving your body enough time to get into the stage of deep sleep needed for your body to function at optimal capacity. To feel more refreshed and energized in the morning, follow the tips below to get more deep sleep:
- Get enough sleep in general. Put yourself on a bedtime schedule where you go to sleep and wake up at the same time each day (including weekends, if possible). You may want to develop a bedtime routine, to help your body recognize when it’s time to start winding down for the night. This may include reading a book, writing in a journal, or making yourself a cup of your favourite herbal tea.
- Move more, sleep deeper. Regular aerobic exercise can help improve the quality of sleep by increasing the amount of slow-wave sleep you get. Aim for at least 20 to 30 minutes of exercise each day, whether that’s walking, cycling or following a video on your favourite fitness app. However, avoid working out too close to bedtime, as this can stimulate your body rather than help you wind down.
- Make it decaf. Stick to drinking water and other decaffeinated drinks, such as herbal tea, before bed. If you’re having trouble sleeping, avoid consuming caffeine for at least six hours before bedtime, and avoid alcohol before bedtime as it can disrupt the quality of your sleep.
- Lights off. Scrolling through your phone or watching television before bed stimulates your brain and can cause distracting thoughts that makes it more difficult to fall asleep. The blue light emitted from these devices can also reduce the amount of time you spend in the deep sleep stage. Aim to turn off all electronic devices 30 minutes to one hour before bed.
- Slip into comfort. The more comfortable you feel, the easier it will be to doze off once your head hits the pillow. Find a comfortable mattress and pillow with appropriate level of firmness, soft bedsheets, and a duvet or blanket cover to keep you feeling cozy all night.