It has always been said that people should get at least 6 hours of sleep if they do not want to compromise their health and well-being . In fact, experts have long recommended that it is necessary to sleep between 6 and 8 hours to perform better the next day and not suffer the effects of lack of sleep.

However, a recent study has shown that sleeping 6 hours is not necessarily good for the human body and can even be as bad as not sleeping as far as cognitive performance is concerned.

Getting 6 hours of sleep could be as bad as not sleeping

These results could therefore indicate that the advice given to us by the experts over so many years was not correct. This study was published in the Journal Sleep and involved 48 adult subjects who were restricted from sleeping. Some participants slept four, some six and some eight hours over two weeks. The research also included another group of subjects who spent three days in a row without sleep.

In order to obtain the results, the participants were tested every two hours on their cognitive performance (unless they were asleep, of course), as well as their reaction time, their level of sleep, the symptoms they were experiencing, and they also answered questions about their mood.

The conclusions of the study were clear. Subjects who were able to sleep for six hours at night performed as poorly as those individuals who were forced to stay awake for three days in a row.

Why six hours of sleep is not enough

What is clear from this research is that the 8 hours of sleep that have always been recommended are the ideal ones for greater performance. It is also clear that subjects who sleep only four hours a night accumulate a sleep deficit and get worse every day.

As for the subjects of the study who slept 6 hours, despite the fact that during the first days they showed a normal cognitive performance, after a few days they began to show a decline in performance . In fact, their performance was as bad as those who had not slept for three days. However, one of the most striking results was that the group of subjects who slept six hours did not seem to have the same perception of sleep as people who had not slept for three days.

Yield decreases after a few days

The first ones did not qualify the fact of having slept that number of hours as something negative nor did they claim to feel sleepiness. On the contrary, the subjects who had not slept for three days did perceive that they were much more tired. This seems to indicate that sleeping six hours may not leave us as tired as not sleeping, however, cognitive performance is still as bad as not sleeping at all.

However, sleeping four hours is even worse than sleeping six hours, as the performance of these participants gets worse every day. In the case of the six hours of sleep, it is from the tenth day that they begin to lose their faculties.

We don’t know how many hours we sleep

It seems, therefore, that a difference of two hours of sleep causes a rather considerable drop in performance, and there are surely many people who do not sleep their 8 hours a day and who may be suffering from these effects. Another curious investigation, this time carried out by the University of Chicago, states that people do not know how many hours they sleep . That is, they might think they are sleeping seven hours and actually are sleeping six.

The results of this research show that people overestimate their sleep time, and are wrong about 0.8 hours on average.

Changing sleeping habits is a complicated task

Experts have long warned of the need for a series of habits to help us sleep better. Exercising, turning off the TV before going to bed or reducing alcohol consumption are some examples. If it is already complicated in itself to adopt these habits, more complicated is to transform your behaviour if you do not know that you need to change your habits to improve your cognitive performance .

One factor that sleep experts place a lot of emphasis on is weight reduction for better sleep. Obesity has a strong correlation with insomnia and sleep apnea, as stated in a study by the National Sleep Foundation in the United States. There is a lot of research that claims that obese workers perform less on the job and are less productive than those who are not.

Better Sleep Habits

In fact, many factors play a role in getting a good night’s sleep: stress at work, problems with your relationship, or drinking stimulating drinks at night

Sleeping well is decisive for our health and, as you have seen, it affects performance in different fields, such as school and work. However, a series of habits can be adopted to help us sleep better. What are they?

1. Taking care of the environment . For example: use a comfortable pillow and mattress and don’t watch TV before going to bed.

2. Do not eat too much at night , because it can make it difficult to sleep.

3. Do not take stimulants when it is close to bedtime.

4. Exercise and improve physical condition.

5. Do not nap to avoid feeling too clear at night.

6. Follow a schedule for going to bed and getting up.

  • You can find out more about these habits in our article: “10 basic principles for good sleep hygiene”