Average Hours Of Deep Sleep – (Examples And Statistics)

For each of us, adequate sleep is important, not only for our relaxation but above all for our health. We will answer the important questions related to it, how long it lasts, what are its phases, and how to improve its quality.

What are the average hours of deep sleep? Our sleep is divided into several phases, it can be assumed that deep sleep lasts about a few tens of minutes. An adult should sleep between 6 and 8 hours, sleep is divided into NREM and REM phases.

What is sleep for us?

Sleep plays a very important role in the life of a human being, it influences his/her development, condition, and beauty. Healthy sleep promotes regeneration of the whole organism, ensures mental and physical balance, and has a positive influence on the work of the nervous system. It is also responsible for the endocrine system, energy conservation, memory, and brain function.

An adequate amount of sleep is therefore essential for the proper functioning of our body. Its demand depends on age, state of health, or even physical activity.

Newborns sleep almost the whole day, small children sleep up to 14 hours, and young people about 8 hours. Adults sleep for about 6-8 hours, while elderly people rest sometimes after only 4 hours.

Sleep phases and their lengths


If we want to know what the average number of hours of deep sleep is, we need to know that sleep consists of successive cyclical stages (usually 4 to 6 times from falling asleep to waking up). These phases are:

  • The NREM phase (non-rapid eye movement sleep), is divided into 4 stages:

1) Falling asleep. The alpha electromagnetic waves emitted by the brain, typical of the time of increased daytime activity, give way to waves of a different frequency, called theta. There is a sensation of sinking, drifting off, and dreaming mixed with sleep. Your eyes are still moving.

2) Abolition of consciousness. The movement of the eyeballs slowly stops, but sleep is still shallow, it is easy to wake up from it.

3) Falling into a deep slow-wave sleep, which is associated with the appearance of so-called delta waves in the brain.

4) Slow-wave sleep, the deepest of all provides a strong disconnection from surrounding reality and the most effective rest. Delta waves become dominant.

  • REM phase (rapid eye movement sleep). Dreams become more intense, brain activity increases, and heart rate accelerates. On the other hand, the muscles become flaccid, so the body becomes practically motionless. Sleep becomes shallower, waking up usually occurs in this phase.

Deep sleep” is usually referred to as the third and fourth stage of the NREM phase, i.e. so-called slow-wave sleep. Sometimes the term is also equated with the entire NREM phase.

Average Hours Of Deep Sleep
Average Hours Of Deep Sleep

Deep sleep – how long should it last?

The entire NREM phase lasts about 1-1.5 hours (usually 80-100 minutes), while the length of deep sleep, understood as the 3rd and 4th stage, is difficult to determine unequivocally – it can be assumed, however, that it is several tens of minutes. In comparison, the REM stage is much shorter and takes about 15 minutes.

However, we should remember that this whole cycle is repeated several times during the night, altogether giving about 7-8 hours of rest.

Deep sleep is characterized by:

  • Low brain activity, reduced heart rate, shallow breathing slowed metabolism and kidney function,
  • Occurrence of dreams of not too high intensity, as well as various types of night fears,
  • The most effective relaxation ensures rapid emotional and physical recovery (including accelerated wound healing).

We already know the average number of hours of deep sleep and the phases of sleep. In this article, you can also read what to do before bedtime to make it healthier for us.

Deep sleep – how to prolong it?

Is it possible to improve the quality of our sleep, so that it has a better impact on our health? Not everything is within our control, but you can do a lot to make your rest longer and more effective. Pay attention to these few things:

  • a regular lifestyle, make sure to spend the day being active and try to use the night for sleep. Go to bed at the same time, short naps during the day are not advisable
  • change your diet, eliminating mainly simple sugars and stimulating drinks such as coffee, strong tea, and cola. Try to eat your last meal at least 2-3 hours before going to bed. This will help calm your body, which will focus on resting
  • avoid prolonged stress, especially in the latter part of the day. In the evening, do not think about work, responsibilities, financial troubles, or family problems
  • physical activity reduces emotional tension, improves the work of body systems, and consequently makes it easier to fall asleep. However, it is important not to exercise late in the evening.
  • use relaxation techniques, do breathing exercises, meditation or yoga before going to sleep, listen to relaxing music
  • have the right bedroom environment, and ensure adequate darkness, silence, natural ventilation, and a temperature of 19-22 degrees Celsius. Also important is the choice of mattress, its hardness is selected according to body weight.

Getting enough sleep is not only important for our well-being but above all for our health. Long-term lack of adequate sleep exposes our body to loss of immunity, increased susceptibility to infections, or problems with remembering.

People who do not sleep for 36 hours or more experience migraine attacks, nausea, vomiting, or dark circles in the eyes. Here you can see statistics that show how sleep length varies by age.

In Summary – Average hours of deep sleep

Healthy and sufficiently long sleep is important for our body and mind. Its length depends on our age, physical activity, or state of health. However, the average number of hours of deep sleep is about several tens of minutes and consists of NREM and REM phases, which follow each other respectively.

We also know how to improve the quality of our sleep, that physical activity, not overeating at night, or various relaxation methods before bedtime are important.

Healthy sleep is another important thing that has a direct impact on our health, others being, for example, sport or a proper diet.

Stacy Reed
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