Each of us spends about one-third of our life asleep. Or, to put it another way, by the time you’re 75, you will have spent 25 years sleeping. Sleep is part of the life of all higher vertebrates. Suppressing sleep for an extended period has dramatic effects on an organism’s physiological equilibrium. In short, sleeping is almost as important as eating or breathing.
We’ve all heard of deep sleep (also known as slow-wave sleep) and how our bodies need it to function properly, but what exactly is it?
What is Deep Sleep?
You can divide sleep into two types: rapid eye movement (REM) and non-rapid eye movement (NREM). You cycle in and out of NREM and REM every 90 minutes or so. This happens about five times a night.
In contrast with Rapid Eye Movement sleep (REM sleep cycle), the main characteristics of slow-wave sleep are absent or slow eye movement, moderate muscle tone, and lack of genital activity.
Features of Deep Sleep
- Electroencephalograph (EEG) demonstrates delta waves (high amplitude, low frequency)
- Consolidation of memories
- High arousal threshold
- Presumed restoration of body and brain
During deep sleep:
- Your heartbeat and breathing slow down
- Your blood pressure drops
- Your muscles relax
- You respond less to external stimuli, like loud noises
- Your brain waves change
What Are Delta Waves for Deep Sleep?
Our brain waves in deep sleep have these long-burst brain waves that are very different from our waking life brain waves. These long-burst brain waves are called delta waves.
Deep sleep is how we convert all those interactions that we make during the day into our long-term memory and personalities. As we get older, we’re more likely to lose these regenerative delta waves. So in way, deep sleep and delta waves are actually a marker for biological youth.
Brainwaves’ sleep music and sounds often include delta waves for deep sleep, such as Delta Pillow Music, Deep Delta Relaxation, Deep Sleep Night, and more. These are specially created with different background music and delta waves for deep sleep.
Why Is Deep Sleep Important?
Deep sleep is important for the consolidation of new memories, and is often referred to as “sleep-dependent memory processing.” Thus, individuals with primary insomnia will have impaired memory consolidation and won’t perform as efficiently as normal patients when completing memory tasks following a period of sleep. In addition, declarative memory is improved with slow-wave sleep, and this includes both semantic and episodic memory.
Sleep affects your whole body. Deep sleep is important for:
- A healthy immune system
- Heart health
- Tissue and muscle repair
- Hormonal balance
How Long Does Deep Sleep Last?
You’ll spend less time in deep sleep as the night goes on. But about 20% of your overall sleep will be deep. Certain things affect how much you’ll get. That includes your age. If you’re under 30, you’ll get about 2 hours of deep sleep a night. People over 65 may only get 30 minutes.
Function of Deep Sleep
Human sleep deprivation studies seem to suggest that the principal function of deep sleep may be to give the brain time to restore itself from its daily activeness.
Yet another function affected by slow-wave sleep is growth hormone secretion, which is always greatest at this stage. Plus, it also creates both an increase in parasympathetic neural activity and a decrease in sympathetic neural activity.
How to Get More Deep Sleep
The most important thing that you can do to increase your amount of deep sleep is to allow yourself adequate total sleep time. Often, individuals will deprive themselves of adequate total sleep. In addition to reducing deep sleep, REM sleep is also shortened.
There is some data to suggest that vigorous exercise can increase or consolidate deep sleep. Some sleep specialists recommend aerobic activities like jogging, running, and swimming. For those who are prone to insomnia, it is best to exercise earlier in the day and not before bedtime.
Besides, keep a habit of listening to proper music and sounds like delta waves for deep sleep as a routine, which will also help you get more deep sleep gradually.