Sleep– a biological need of the body. A state in which there is stillness and the abolition of consciousness; it appears cyclically and passes in a circadian rhythm.

Recommended amount of sleep


Newborns (0- 3 months)
14- 17 hours

Toddlers (1- 2 years)

11- hours

Infants (4- 11 months)

12- 15 hours

Preschoolers (3- 5 years old)

10- 13 hours

School age children (6- 13 years old)

9- 11 hours

Youth (14- 17 years old)

8- 10 hours

Younger adults (18- 25 years old)

7- 9 hours

Adults (26- 64 years)

7- 9 hours

Older adults (65 years and over)

7- 8 hours

Sleep is not uniform, it occurs in five phases: waking up, N1, N2, N3 and REM.

About 75% of sleep occurs in the NREM phase and most of it occurs in the N2 phase.

NREM and REM sleep occur cyclically during the night, creating the so called sleep cycles.

During the night, a person goes through four to six sleep cycles,

with the progression of sleep phases in the following order: N1, N2, N3, N2, REM.

Sleep stages



Stage 1 sleep
it is a transitional stage between wakefulness and sleep, when a person falls asleep. In this phase, the heart rate and breathing slow down, and the activity of the body and brain begins to slow down. This stage lasts about 1 to 7 minutes and accounts for about 5% of sleep.


Stage 2 sleep
the body enters a state of deep relaxation, which also includes a drop in temperature and a slowdown in breathing and heart rate. It is characterized by the presence of sleep spindles, K complexes, or both. Sleep in phase 2 lasts from 10 to 25 minutes- it increases with each subsequent cycle. covers approximately 45% of total sleep.


Third stage of sleep (stage 3 sleep) and fourth stage of sleep (stage 4 sleep)

it is called deep sleep. During this time, muscle tension, heart rate and breathing rate decrease significantly. During early sleep cycles, stages usually last between 20 and 40 minutes. as sleep passes, these stages become shorter in favor of the REM phase. This phase accounts for approximately 25% of all sleep.


during this phase a person dreams. Skeletal muscles are atonic and immobile, breathing becomes shallow and rapid. Blood pressure and heart rate increase. This phase occurs approximately 90 minutes after the sleep cycle begins. Each REM cycle becomes longer and longer throughout the night. The first part lasts about 10 minutes, and the last one up to an hour. This phase accounts for 25% of all sleep.

Improving sleep quality



Taking care of your circadian rhythm
fixed times of falling asleep in the evening and waking up in the morning.



Limiting the effects of blue light
1-2 hours before bedtime- phone, computer, TV and others;

they block the production of melatonin (using blue light filters will be helpful).



Diet, supplementation and hydration
a healthy diet (balanced, providing the appropriate level of micro and macro elements;
rich in healthy fats, protein and high quality carbohydrates).
Avoiding eating large or heavy meals before bed.
Adequate hydration of the body during the day to reduce the need to drink large amounts of fluids before bed.
Supplementation helpful in falling asleep, relaxation and stress reduction.



Physical activity

preferably 30- 60 minutes outdoors during the day, but never before bed.



Stress reduction

cortisol worsens the quality and length of sleep and negatively affects regeneration.



Sleep hygiene

adequate ventilation of the bedroom, room temperature 18- 20 degrees C, clean bedding, comfortable mattress, deep darkness.



Avoiding naps

at least 6 hours before bedtime, they may affect the circadian rhythm.



Limiting stimulants

tobacco and alcohol, coffee- about 6 hours before bedtime.



Relaxation before bed

Breathing techniques, meditation, reading, baths and other relaxing activities may be helpful.

Sleep: recommended amount of sleep, sleep stages. Sleep quality, improve sleep quality.