How much sleep do we really need ??

Most of us sleep approximately one-third of our lives. Do we really have to sleep so long? We rarely
encounter people who sleep much less time in our environment. Is it possible to shorten our sleep?
What kinds of problems we encounter if we sleep a shorter period of time?
The researches conducted In recent years made it possible to answer menu of the questions above. lthough sleep duration varies from person to person; it is known That this period vary from 4 hours to 11 hours. Sleep duration varies from person to person with the influence of genetic factors. Except certain limits, it is not possible to change this duration determined when we were born. when we have to shorten the time, we are faced with unwanted symptoms arisen from sleep deprivation.
The best evidence indicating the presence of genetic transmission is determining that identical twins have exactly the same sleep duration.

As a result of the researches it is known that the vast majority of the population in USA  (75%) has a habit of sleeping for 7-8 hours. You hear very often from the press that Some of the famous people sleep very short time. Some of them. for example Napoleon. Churchill was recorded in the history books with their short sleep duration. There are not too many people whose functions do not change the following day after they sleep short time. It is know that; only 10% of population in USA sleeps less than 6 hours. when we talk about short time sleepers, we should exclude the persons who sleep less than 6 hours at weekdays while they extend their sleep time up to 8-10 hours at weekends.

Persons who sleep more than 8 hours are seen more often than short sleepers in the society and their ratio is as high as 15%. Sleep structures of short time sleepers and long time sleepers are different from each other.

Short time sleepers sleep a kind of sleep which is consisted of more
Intensely slow, deep sleep and REM sleep phases. The number of night being awake and the 2nd phase rate is decreased in these persons. Therefore. it can be said that; they sleep a short-term but moreefficient sleep. Long time sleepers sleep deep slowed sleep which is called real sleep.

Long sleepers, people who need more time to work, usually intend to shorten their sleep duration. However, it is not possible to shorten sleep duration under a certain ratio. In a study conducted with university students, it was not possible to shorten their sleep duration in a short time of period. The following day after the study, It was detected in some complaints of study subjects such as tiredness, fatigue, difficulty in concentration and memory disorders. The participants of study had fallen asleep at inappropriate time because they could not resist against their sleep necessity. However, another study proven that; sleep duration can be reduced in a long time of period, without exceeding 1-2; and this reduction do not cause any damage on the performance of study participants. It should be remembered that; this study was conducted with young participants. It is encountered various symptoms an child and elderly people as a result of any reduction in their sleep duration.