Deep sleep is one of the sleep stages that you usually enter several times each night. Though, its nature is somewhat less well-known than the more dramatic “dream sleep”. While we are very much aware of dream sleep today, the nature of deep sleep continues to be a mystery.
We all know that we should sleep for seven to eight hours a day. Not completing the hours can significantly impact our ability to perform our daily tasks properly. You can get fatigued and feel too tired to work. Moreover, your body might not function well if you’re not getting enough deep sleep.
Fortunately, there are practical ways you can improve your sleep quality, starting with understanding what’s keeping you from reaching deep sleep. You can adjust your nighttime routine to explore calming sounds like white noise for infants, which also work wonders for adults. Small changes in your habits can make a big difference in how well you sleep and how energized you feel the next day.
Introduction: The Critical Role of Deep Sleep in Brain and Body Health
Deep sleep stage is also known as delta sleep, slow-wave sleep, or, more recently, N3. It is called delta sleep because of the presence of high-amplitude, low-frequency delta waves that are seen to occur in the EEG.
It has a major role to play in maintaining overall health. Without proper sleep, your health will start deteriorating slowly. The following are just some of the ways good sleep helps your body stay active.
- It helps enhance your metabolism
With deep sleep, your metabolism rates get increased. Proper digestion is also ensured with quality sleep.
- It helps improve memory
Your short-term and long-term memory will also improve if you indulge in deep sleep every day.
- It simplifies cell regeneration
Cell regeneration gets easier with deep sleep. A regular deep sleep keeps you healthy, and you will be unlikely to suffer from any diseases.
- It boosts your immune system
Individuals with a weak immune system are likely to suffer a lot of problems. When you sleep for 8 hours regularly and ensure a deep sleep, your immune system will gradually improve.
What is “Enough”? Understanding the Ideal Percentage of Deep Sleep
Deep sleep is the third stage of non-rapid eye movement (NREM) sleep. It usually lasts between 70 to 90 minutes, taking place during the first hours of the night. It is characterized by moderate muscle tone, slow or absent eye movement, and lack of genital activity. Deep sleep is considered important for memory consolidation, declarative memory, and the recovery of the brain from daily activities.
For healthy adults, 13% to 23% of sleep should be deep sleep. For an average of 8 hours of sleep, that is roughly 60 to 110 minutes spent in deep sleep. Most adults spend close to 25% of each night in REM sleep.
The Prime Suspects: Common Lifestyle Habits That Are Stealing Your Deep Sleep
If you’re not getting enough deep sleep, your daily habits may be the real culprit. Even small lifestyle choices can disrupt your body’s ability to enter and maintain deep sleep. Here are some of the most common lifestyle habits that are stealing your deep sleep:
- Late-night screen time
- Caffeine and alcohol consumption
- Irregular sleep schedule
- High stress and overthinking
- Poor sleep environment
- Lack of physical activity
The Melatonin Connection: How Light Exposure Disrupts the Deep Sleep Signal
Did you know that exposure to light during sleep makes it difficult for your brain to achieve deeper stages of sleep? The more shallow or light sleep you get at night, the more your brain oscillations that allow you to get to deeper sleep are negatively affected.
When you’re exposed to light at night, your body’s circadian rhythm is thrown off. As a result, your brain produces less melatonin hormones which otherwise allows you to get sleep. It may be difficult for you to fall asleep and stay asleep because your brain won’t produce enough sleep-inducing melatonin.
Even if you were able to sleep with lights on, you may not get enough REM sleep. The other stage of sleep is non-REM, which includes light sleep and deep sleep. A lack of deep sleep from light exposure has been linked to the following side effects.
- Depression
- Obesity
- Accidents
- Increased risk of chronic illnesses
Environment Matters: Optimizing Temperature, Sound, and Darkness for Stage N3
The Stage N3 depends heavily on external factors like temperature, sound, and light. So, if you’re not getting enough deep sleep, these factors might be the reason why. Here’s how you can help your body enter and maintain this stage more easily.
1. Set the right temperature
One way to promote deep sleep is having a cool room. Sleep experts suggest keeping your bedroom between 60°F and 67°F (15°C–19°C). During deep sleep, your core body temperature naturally drops, signaling your brain it’s time to wind down. On the other hand, overly warm environments can interrupt this cooling process.
2. Control the background noise
Noise disruptions like traffic, snoring, or noisy households can prevent your brain from reaching deep sleep. Consider using white noise for infants, which world just as well for adults, to mask background disturbances.
3. Implement total darkness
As mentioned before, light exposure can interfere with melatonin production and fragment your sleep cycle. Invest in blackout curtains, eye masks, or dimmable lamps with amber tones to maintain darkness throughout sleep.
Diet and Timing: The Impact of Late Meals, Caffeine, and Alcohol on Sleep Quality
What you consume throughout the day has a direct effect on how easily your body transitions into deep sleep.
Eating heavy meals too close to bedtime can make it difficult for your body to fully relax. When your digestive system is still working, it raises your core body temperature, which interferes with the natural cooling process needed for deep sleep. It is suggested that you finish your last meal two to three hours before bed.
Caffeine is another reason why you’re not getting enough deep sleep. It has stimulating effects that can last for up to eight hours, delaying the onset of deep sleep and shortening the amount you get. Consider cutting off caffeine after lunchtime and replacing it with water or herbal teas instead.
Alcohol, on the other hand, can be sometimes deceptive. While it may help you fall asleep faster, it disrupts the sleep cycle by reducing both REM sleep and deep sleep during the first half of the night, then causing frequent awakenings in the middle of the night. Limit alcohol intake, especially within three hours of bedtime.
Stress and Anxiety: Addressing the Mental Barriers That Keep Your Brain Active
Stress and anxiety can also be the reasons why you’re not getting enough deep sleep.
When your mind is racing with thoughts, your body remains on high alert, releasing stress hormones like cortisol and adrenaline that prevent you from fully relaxing. This heightened state of mental activity makes it difficult for your brain to transition into Stage N3, the deep sleep phase responsible for restoration and recovery.
Chronic stress also disrupts your body’s circadian rhythm, causing irregular sleep patterns and frequent awakenings throughout the night. Even if you manage to fall asleep, your brain may stay semi-active, limiting the amount of truly restorative deep sleep you get. Over time, this can lead to fatigue, mood swings, and reduced focus, creating a frustrating cycle where sleeplessness fuels more stress and anxiety.
Simple, Science-Backed Strategies: Actionable Steps to Boost Your Deep Sleep Tonight
If you’re not getting enough deep sleep, try these simple, science-backed strategies to help you achieve those deeper stages of sleep.
- Stick to a consistent sleep schedule
- Limit screen exposure before bed
- Create a sleep-friendly bedroom
- Avoid caffeine and alcohol in the evening
- Exercise regularly
- Watch your evening meals and drinks
- Wind down gradually
