Deep sleep, also known as slow-wave sleep (SWS), is one of the essential phases of the sleep cycle. It is characterized by slow, high-amplitude delta brain waves on an electroencephalogram (EEG). This stage is a time when your body and mind engage in a deep restorative process. During deep sleep, the body carries out physical repair, immune system strengthening, memory consolidation, and the brain cleanses itself of metabolic wastes from functioning during the day. It’s also a time when hormones are regulated and the heart and mind experience a period of reduced activity.
Deep sleep only occurs in the latter part of each sleep cycle, and only in the first few hours of sleep (see stages 3 and 4 in the figure below). It is the opposite in the sleep cycle from the REM/vivid dreaming stage, which is the most wakeful part of sleep. As the night goes on, deep sleep decreases and REM sleep increases in frequency and duration.
How Much Deep Sleep Do People Need?
The amount of deep sleep you need can vary based on factors like age and individual differences. Adults should aim for about 10-15% of their total sleep time in deep sleep. This typically equates to 1.5 to 2 hours of deep sleep per night, but some people may naturally have more or less.
Children and teenagers tend to have more deep sleep, while as you age, the amount of deep sleep may decrease. The key is to ensure you get enough quality sleep overall, as this will naturally include the necessary deep sleep cycles.
How Can Someone Know If They’re Getting Enough Deep Sleep?
Diagnosing a lack of deep sleep typically involves a combination of self-assessment, clinical evaluation, and, in some cases, sleep studies. If you feel your total sleep time is adequate (between 7 to 9 hours per night) but you experience symptoms of sleep deprivation such as waking unrefreshed, difficulty focusing, learning, or carrying out everyday activities, it could be a sign of insufficient deep sleep. It could also be sleep apnea or another issue causing the sleep deprivation symptoms so a sleep study is often necessary to fully diagnose the problem. A sleep study, also known as polysomnography, may be used to assess your sleep patterns and diagnose sleep disorders. During a polysomnogram, you’ll spend a night in a sleep clinic where various physiological parameters are monitored while you sleep. This includes brainwave activity (to identify sleep stages, including deep sleep), eye movements, heart rate, muscle activity, and breathing patterns. Polysomnography can help determine if you’re not getting enough deep sleep and whether sleep disorders such as sleep apnea, restless legs syndrome, or narcolepsy may be contributing to your sleep problems. It’s a highly accurate way to assess sleep architecture and diagnose specific sleep disorders.
Why Do People Need Deep Sleep?
Deep sleep is vital for your overall health and well-being. Here are some compelling reasons why you need it:
- Physical Restoration: Deep sleep allows your body to repair and rejuvenate. It’s a time for muscle and tissue recovery, making it crucial for physical health and growth.
- Immune Function: Deep sleep strengthens your immune system, helping you fight off infections and illnesses more effectively.
- Memory Consolidation: It’s during deep sleep that your brain processes and organizes the information you’ve acquired throughout the day, transferring it from short-term to long-term memory.
- Cognitive Function: Deep sleep is associated with improved cognitive function, including problem-solving, creativity, and decision-making. It prepares your brain for optimal performance during your waking hours. Deep sleep is also the time of the night when the brain will clean out metabolic wastes that if not cleared out may accumulate and increase the long-term risk of dementia and/or Alzheimer’s disease.
- Emotional Regulation: This stage contributes to emotional stability by regulating mood and reducing feelings of anxiety and stress.
- Hormone Regulation: Deep sleep plays a role in regulating essential hormones such as cortisol and insulin, which are crucial for stress management and blood sugar balance.
- Heart Health: Deep sleep reduces blood pressure and heart rate, allowing your cardiovascular system to rest and recover, promoting heart health.
How Can Someone Get More Deep Sleep Naturally?
Getting more deep sleep is essential for a healthier and more productive life. Here are some tips to help you achieve that:
- Create a Consistent Sleep Schedule: Go to bed and wake up at the same time every day, even on weekends. This helps regulate your internal body clock.
- Optimize Your Sleep Environment: Make your sleep space comfortable and conducive to rest. Keep the room cool, dark, and quiet.
- Limit Screen Time Before Bed: The blue light emitted by phones and computers can disrupt your sleep patterns. Try to avoid screens for at least an hour before bedtime.
- Regular Exercise: Regular physical activity can improve sleep quality, but avoid intense workouts close to bedtime.
- Watch Your Diet: Avoid heavy meals, caffeine, and alcohol close to bedtime, as they can interfere with deep sleep.
- Relaxation Techniques: Practice relaxation techniques like deep breathing, meditation, or yoga to reduce stress and improve sleep quality.
- Limit Naps: While short naps can be refreshing, long or irregular daytime naps can interfere with nighttime deep sleep.
- Pink Noise: Recent research published in the European Heart Journal indicated the presence of pink background noise significantly increased slow wave activity, and more importantly, this increase correlated with improved functioning of the left ventricle of the heart, the key chamber of the heart that pumps freshly oxygenated blood to the rest of the body.
Incorporating these habits into your daily routine can help you get more deep sleep, enabling you to wake up feeling refreshed, alert, and ready to tackle the day.
Deep Sleep Recap
In conclusion, deep sleep is a critical component of a healthy sleep cycle. Prioritizing it can lead to better physical health, improved cognitive function, and emotional well-being. By understanding the importance of deep sleep and making simple adjustments to your lifestyle, you can unlock your full potential and live a more fulfilling life. If you’re still unsure if you have an issue with deep sleep or feel like you need some help figuring things out, come see us in Phoenix, Scottsdale or Gilbert, Arizona.