Increasing the amount of deep sleep is important for overall health and well-being. Deep sleep, or slow-wave sleep (SWS), is the most refreshing sleep stage in the sleep cycle and is important for physical recovery, memory consolidation, and immune functioning.
Studies show that deep sleep is typically about 13 to 23% of total sleep in adults, but often ,they are not able to get enough. The Centers for Disease Control and Prevention (CDC) reports that approximately 35% of American adults report getting less than the recommended 7 hours of sleep per night, and are probably not getting quality deep sleep either.
So, if you're asking yourself How do I get more deep sleep, it is a combination of lifestyle changes, sleep routines, and sleep environment changes.
With everything from timing your sleep, not having distractions and stressors to worry about, this guide will provide practical strategies to maximize your deep sleep and help you wake up feeling refreshed and full of energy. Let's find out how you can improve sleep quality to take advantage of all the rejuvenating properties of deep sleep.
What is Deep Sleep?
Deep sleep, sometimes referred to as slow-wave sleep (SWS) or delta sleep, is the most recuperative stage of the sleep cycle. Deep sleep happens during stages three and four of non-rapid eye movement (NREM) sleep.
During deep sleep, your brain activity decreases significantly while the body focuses on restoration, repair and immune function. This phase is crucial for physical recovery, muscle development, tissue repair and even consolidation of memories.
If you're getting the recommended amount of sleep (7-9 hours of sleep), deep sleep represents about 1 to 2 hours of deep sleep each night. The amount of deep sleep you get may vary based on age, quality of sleep and overall health. Deep sleep tends to diminish as we grow older.
Younger adults may receive more deep sleep than older adults, who generally receive less. Deep sleep is essential for the process of physical recovery, processing memories and general well-being.
During this stage, heart rate, respiration and core body temperature decrease, which facilitates deep relaxation and rejuvenation. In addition to being critical for overall well-being and recovery, deep sleep promotes proper mental function, regulates mood, assists immunity, and balances hormones.
What are the Stages of Sleep?
There are two types of sleep: Non-Rapid Eye Movement (NREM) and Rapid Eye Movement (REM) sleep, and these stages cycle throughout the night. There are four stages of sleep:
Stage 1 (NREM) – This stage of sleep is light sleep, lasting 5-10 minutes. You are in the transition of being awake and not being awake, with muscle activity slowing down. It is easy to wake up during this period.
Stage 2 (NREM) – This stage of sleep is a deeper state of sleep than stage 1, lasting roughly 20 minutes. Your body temperature and heart rate are decreased with brain activity slowed compared to stage 1. Stage 2 sleep is where sleep spindles occur (these are spurts of brain activity) that solidify memories.
Stage 3 (NREM) – This is deep sleep or slow-wave sleep. This is the most restorative stage of sleep, where your body repairs itself, and growth hormones are released. You will spend 20-40 minutes in stage 3 of sleep.
Stage 4 (REM) – REM sleep is primarily where dreaming occurs. Brain activity is heightened, while muscles are temporarily paralyzed so you don’t act out your dreams. REM sleep is important for memory consolidation and regulation of emotions.
Each stage of sleep switches in cycles that takes about 90 minutes to complete a full cycle of all stages of sleep. You should typically complete 4-6 cycles per night.
What are the Benefits of Deep Sleep?
Deep sleep is vital for your body and mind for several reasons. Below are some of the major benefits:
Physical Restoration: During deep sleep, your body repairs tissues, grows muscle mass, and supports your immune system. This restorative cycle is necessary for physical healing and energy levels.
Memory and Learning: The brain retains and processes information acquired during the daytime while in deep sleep. This improves memory, learning, and brain performance associated with problem-solving.
Hormone Regulation: Deep sleep promotes the secretion of growth hormone, which is necessary for muscle growth and repairing tissues. It also regulates hormones associated with stress and appetite.
Emotional Health: Adequate amounts of deep sleep are important for mood and emotional health. Additionally, deep sleep promotes improved stress tolerance, reduces irritability, and increases mental health and well-being.
Improved Immune Function: Deep sleep helps the immune system fight infection and illness more effectively.
Better Physical Performance: Deep sleep maximizes physical performance by providing an opportunity for essential muscle and tissue repair, minimization of fatigue, and a general increase in endurance and strength.
What Happens When You Don’t Get Enough Deep Sleep?
Not getting enough deep sleep is harmful to your physical and psychological health. Here is what occurs when you repeatedly miss out on deep sleep:
Physical Fatigue: Deep sleep is essential for physical recovery. If you do not receive enough deep sleep, you will feel tired, sore, and will experience reduced energy levels during the day.
Impaired Immune Function: Deep sleep is a critical aspect of the immune system. Without deep sleep, you are more susceptible to infection and illness.
Cognitive Impairment: Without enough deep sleep, your ability to store memories and cognitive function is impaired. It will be harder to focus, memorize, and solve problems.
Mood Disturbance: A chronic deficit of sleep, particularly in terms of deep sleep, can create irritability, an increased response to stress, sleep anxiety, and can also contribute to depression.
Hormonal Disorders: Sleep deeply may play a role in regulating hormones governing growth, stress, and appetite. Insufficient deep sleep can affect the balance of hunger-related hormones, which can subsequently lead to weight gain, higher cravings, and stress.
Increased Risk of Chronic Disease: Significant sleep disruptions, but especially loss of deep sleep, can contribute to increased risk of chronic disease, including heart disease, diabetes, and high blood pressure.
How Much Sleep is Enough Deep Sleep?
Deep sleep duration varies by age group and individual needs. Most adults (18 - 64) should aim for 1 - 2 hours of deep sleep a night. That is measured at approximately 13 - 23% of the recommended 7-9 hours of sleep each night.
Adults aged 65 and older may get slightly less deep sleep, on average around an hour or less, but still gain value from any deep sleep they get. Teens (14-17) require deep sleep at a greater duration of 1.5 - 2 hours, as their bodies require more deep sleep for the body for growth and recovery.
Children (6-13) require even more deep sleep than teens, typically closer to around 2 hours, as they have high growth demands. These are general guidelines, and individual need will vary. However, it is critical to have access to 1 - 2 hours of deep sleep each night as it contributes to overall health, memory storage, and body repair.
How Do You Know if You Are Getting Enough Deep Sleep?
Important physiological factors, such as breathing rate, oxygen levels, body movements, brain waves, and heart rate, while sleeping can help provide a clear understanding of whether you are getting sufficient deep sleep when assessing your sleep quality.
Breathing Rate: Breathing becomes slower and more regular during deep sleep. Exhibit shallow or irregular breathing could indicate poor sleep quality or interruptions, for example, due to sleep apnea, that prevents you from entering deep sleep for sufficient amounts of time.
Oxygen Levels: Deep sleep is often associated with healthy oxygen levels. Significant drops in oxygen levels while you sleep could indicate sleep apnea or another disorder that interferes with your body's capacity to achieve and maintain deep sleep.
Body Movements: When you are deeply asleep, your body moves less. Your sleep cycle and overall amount of deep sleep time may be impacted if you are constantly rolling over or waking up during the night.
Heart Rate: Heart rate slows significantly during deep sleep as the body enters a state of relaxation. Reduced sleep quality, stress, or other sleep disorders may be indicated by elevated or irregular heart rate while sleeping.
Brain Activity: Brain functions during deep sleep show slow, large brain waves (delta waves). Slow-wave sleep is what distinguishes deep sleep, and is essential for physical and mental restoration. Sleep monitor devices track and detect brain ways to identify how deep your sleep is.
How Can I Get More Deep Sleep?
To make sure you get a good night's sleep:
- Go to sleep and wake up around the same time every day, including weekends. Frequency can help regulate your body's internal clock and increase sleep quality.
- Do something calming right before bed, such as reading, taking a warm bath, and practicing relaxing activities for example: deep breathing or meditation to let your body know it's time to sleep.
- Make your bedroom dark, quiet, and cool. Use blackout curtains, earplugs, cooling pillows, or a white noise machine to assist with distractions.
- Light from phones, tablets, and computers emits blue light disrupting the body's ability to produce melatonin, a hormone that causes sleeping. Avoid screens at least 30 – 60 minutes prior to sleeping.
- Avoid large meals, caffeine, and alcohol forbidding a usual bedtime, as they may result in discomfort, heart rate elevation, and disturbance during the sleep cycle.
- Daily exercise contributes to good quality sleep, however, do not engage in vigorous exercise before bed, as you may become overstimulated and it may take you longer to fall asleep.
- Spend some time doing some relaxation techniques, such as journaling, yoga, or mindfulness, to calm your mind and be ready for sleep.
Final Thoughts
Deep sleep is essential for sustaining overall health and well-being. It is considered the most restorative phase of the sleep cycle, as it allows physical rejuvenation, mental functions, emotional stability, and immune functionality.
However, most people living in modern life circumstances are not able to attain enough deep sleep, which manifests as tiredness, memory issues, and poor immune system function.
Deep sleep can be increased in both quantity and quality simply by incorporating some changes in your daily life-such as incorporating a consistent bedtime routine, modifying your bedroom environment, and practicing stress management techniques.
