Study concludes that sleeping 6 hours is just as bad as not sleeping at all
Science puts us on the spot: too little sleep seriously harms our health.
It has always been said that people should sleep at least 6 hours if we do not want to compromise our health and wellbeing.. 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 may even be as bad as no sleep at all as far as cognitive performance is concerned.
Sleeping 6 hours could be just as bad as not sleeping at all
These results could therefore indicate that the advice we have been given by experts for so many years was not correct. This study was published in the Journal Sleep and involved 48 adult subjects whose sleep hours were restricted. Some participants slept four, others six and others eight hours for two weeks. The research also included another group of subjects who went 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 experienced and they also answered questions about their mood.
The conclusions of the study were clear. Subjects who were able to sleep for six hours a night performed just as poorly as those who were forced to sleep for six hours a night. than those individuals who were forced to stay awake for three days in a row.
The reason why six hours of sleep is not enough
What is clear from this research is that the 8 hours of sleep that has always been recommended is the ideal time to have the best performance. It is also clear that subjects who sleep only four hours a night accumulate a sleep deficit and get worse each day.
As for the subjects in the study who slept 6 hours, although during the first few days they showed normal cognitive performance, after a few days they began to show a decline in cognitive 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 those who had not slept for three days.
Performance declines after a few days
The former did not rate the fact that they had slept that number of hours as something negative, nor did they report feeling drowsy. 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 just as bad as not sleeping at all.
Now, 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 6 hours of sleep, it is from the tenth day that they begin to lose their faculties.
We do not know how much sleep we get
It seems, therefore, that a difference of two hours of sleep causes a quite considerable drop in performance, and there are certainly many people who do not sleep their 8 hours a day who may be suffering from these effects. Another curious piece of research, this time carried out by the University of Chicago, states that people do not know how many hours they sleep. That is, they may believe they sleep seven hours and in reality they are sleeping six.
The results of this research show that people overestimate their sleep time, and are wrong by 0.8 hours on average.
Changing sleep habits is a complicated task
Experts have been warning for some time that it is necessary to make a series of habits that help us sleep better. Practicing physical exercise, turning off the television before going to bed or reducing alcohol consumption are some examples. If it is already complicated in itself to adopt these habits, it is even more complicated to transform your behavior if you do not know that you need to change your habits to improve your cognitive performance..
One factor that sleep experts stress a lot 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. Much research has shown that obese workers perform less well at work and are less productive than those who are not obese.
Habits for better sleep
In reality, there are many factors involved in getting a good night's sleep: stress at work, problems with your romantic relationship or drinking stimulating beverages at night.
A good night's sleep is decisive for our health and, as you have seen, it affects our performance in different fields, such as school or work. However, you can adopt a series of habits that help you sleep better. What are they?
1. Taking care of your environment. For example: use a comfortable pillow and mattress and do not watch TV before going to bed.
2. Do not eat large meals at nightas they can make it difficult to sleep.
3. Do not take stimulants when bedtime is approaching.
4. Do physical exercise and improve your physical condition.
5. Do not overdo it with the nap to avoid feeling too sleepy at night.
6. Follow a schedule to go to bed and get up.
- You can learn more about these habits and some others in our article: "10 basic principles for a good sleep hygiene".
(Updated at Apr 13 / 2024)