How Different Sleep Phases Effect our Body

February 21, 2019

How much Deep Sleep is Important?

Healthy sleep is essential for the human body. Insufficient night rest can lead to fatigue, lack of concentration and cardiovascular disease. Find out with us what sleep phases there are and why the deep sleep phase is especially important in order to stay healthy.

Fixed Rhythm

The human organism sleeps at a fixed rhythm with different sleep phases. Each is recognizable by a typical brain wave pattern. But we don’t even get to know that our night’s sleep is like this. But the architecture of our sleep determines whether we sleep healthy or not.

A healthy night’s sleep includes the following five phases of sleep:

Phase 1: Sleep-in Phase

At this stage, the organism relaxes and calms down more and more. Breathing becomes deeper and the pulse slows down. Many people experience this sleep phase, which is perceived in a dream-like way, as a time of falling or getting more and more “heavy”. Since sleep is still very superficial at this time, even small disturbances can cause us to wake up. Dinners before bed time, too much coffee, bright light, the consumption of alcohol before bedtime and everyday stress or exam anxiety can disturb sleep at this point. Sleep disruptions can be the result.

Phase 2: Light Sleep Phase

In the second phase of sleep, brain activity is limited to low frequencies. The muscles are relaxed, we sleep almost without eye movements and the transition to the restful sleep phases begins. Sleep research previously assumed that only deep sleep is important for memory formation. It is now known that even light sleep phases are important for processing information and are just as important for learning.

About half of the total sleep is spent by humans in the first two phases of sleep. Even in the light sleep phase, sleep is still superficial, so that small stimuli, sounds or other disturbances still wake us up quite quickly. Here, too, sleep problems are often caused by stress.

Phases 3 and 4: Deep Sleep Phase

At this stage of sleep, which is divided by sleep researchers into a phase of moderate sleep and one of very deep sleep, we recover particularly well. We sleep deep and firm. The heartbeat and breathing rate slow down and blood pressure drops. Our brain and muscle activity is kept to a minimum and we breathe rhythmically.

Many people are very difficult to wake up during the deep sleep phase and only wake up very slowly. For mental and physical recovery, the most precious time begins at night. That’s why it’s so important for restful sleep. The proportion of deep sleep is very high at the beginning of the night, but decreases during sleep.

Those who drink too much alcohol or have sleep apnea hardly reach this deep sleep and often suffer from sleep disturbances.

Phase 5: Rem-Phase

The deep sleep phase is followed by a short light sleep phase, which leads directly into the REM sleep phase. It is also called the dream sleep phase. Many researchers assume that during this time we process information and emotional impressions. Characteristic of REM are the fast eye movements under closed eyelids. REM is the abbreviation of the English term “rapid eye movement”, which means “rapid eye movement” and refers to this characteristic. At this stage, brain activity accelerates significantly and heart rate increases again. Breathing is shallow and fast. At the same time, however, all muscles and the muscle twitching that many know from their sleep phase are no longer possible. The slackening of the muscles is a natural protective mechanism of our body.

Since we dream a lot at this stage, we could actually carry out movements (sleep walking) and hurt ourselves. We also dream in other deep sleep phases, but in the REM-Phase it is longer and more intense. Although we dream, we are still easy to wake up during this sleep phase. Disorders at this stage can lead to difficulty concentrating and reduced learning capacity.

The Sleep Phases are Repeated Several Times in one Night

If we are healthy, the sleep phases are repeated five to six times a night. A complete phase cycle takes about 90 min plus or minus 10 min. At the beginning of the night, deep sleep dominates. Only in the second half of the night and towards the end of the night the REM phases are extended and the body prepares to wake up. Our sleep behavior during the phase cycles is like a staircase: first light sleep, then deep sleep and at the lowest level the REM sleep phases.

How Much Deep Sleep Should You Have?

We should spend 20 to 30% of our total sleep in deep sleep in order to stay healthy. If deep sleep is shortened, for example due to insomnia, health impairments may occur.

Why is Deep Sleep so Important and What Factors Influence It?

In deep sleep, the brain emits delta waves. They allow the brain maximum rest. Our body is also completely relaxed. During deep sleep, the body releases growth hormones that stimulate the strengthening of the immune system and the repair of cells to stay healthy. In addition, metabolism is regulated at this stage.

We need this absolutely relaxed stage, where the level of the stress hormone cortisol is lowest, in order to regenerate our immune system, strengthen our performance and recover extensively.

In addition, in deep sleep phases, a transfer of the learned and experienced takes place from short-term to long-term memory. Healthy sleep therefore depends on the quality and length of the deep sleep phase.

Factors that affect deep sleep and often cause sleep problems:

  • increased age
  • night sweating
  • Stress
  • restless sleeping atmosphere
  • bright sleeping environment
  • frequent position changes
  • beds that are not properly matched to the body
  • excessive alcohol consumption
  • Coffee in the evening
  • full stomach

How Can I Improve Sleep Quality and Sleep Healthy?

A good bed, which is individually adapted to the sleep needs and the physique of the person, is of great importance for the deep sleep phase and basis for being able to sleep healthy. This is why we use linseed oil for our beds. It emits a pleasant aroma and is non-toxic. When we start designing here at Quagga Designs, our aim is to eliminate any metal parts. Although it is not scientifically proven, we believe that there might be a correlation between cancer and the electromagnetic fields given off by metal parts. If you are interested please read this blog written by R. Douglas Fields, PH. D.

A balanced day-night rhythm means that the sleep phases are allowed to proceed undisturbed. People who are exposed to stress a lot in everyday life often suffer from sleep disturbances and sleep problems. For them, it is important to relax as much as possible before going to bed. In addition to a good bed and avoiding sleep-reducing and stressful factors, the bedroom plays a major role and should not go unnoticed.

In addition to a good bed, the right selection of duvet, pillows and bed linen play an important role. All of these elements together contribute to a restful and healthy night’s sleep. Care should be taken when choosing the right beds.

If you are not sure which bed is right for you, give us a call at 905.324.2098 or email me at

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