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Not all the time we spend in bed are we asleep. And not all the time we spend sleeping are we enjoying quality sleep. However, getting enough hours of good quality sleep is key to physical and emotional well-being.

One bad night’s sleep is sufficient to understand the direct relationship that exists between plenty of restful sleep and wellbeing.

Having a sleepless night inevitably leads to a certain degree of irritability, a lack of concentration, and even feeling poorly and headaches. Of course, where, instead of sporadic episodes, this becomes a recurrent – even habitual – event, then we are talking about insomnia. That is to say, a disorder suffered by over four million adults in Spain, according to the Spanish Association of Neurology (SEN). Data from the Spanish Association of Neurology reflect the fact that 25-35 percent of the adult population suffer intermittent insomnia and 10-15 percent have chronic insomnia.

In such cases, we are looking at possibly serious health consequences. Over the last decade, several studies have shown that “insomnia is associated with adverse health effects, such as obesity, type 2 diabetes, hypertension and cardiovascular diseases,” in the words of Jesús Pujol, a member of the Insomnia Working Group of the Spanish Sleep Society (SES). This relationship has to do with disruption of the circadian rhythm and insulin secretion, among other things. Nor should it be forgotten that a lack of sleep also leads to a reduction in our quality of life and daily performance, cognitive and memory deficits, as well as anxiety and depression problems.

From all this it follows that, in order to enjoy a better quality of life, it is necessary to sleep longer. However, this is becoming increasingly rare, according to recent sociological survey data from the CIS, which reveals that, on average, Spaniards sleep less than seven hours a day. And just over ten percent say they do not even sleep for six hours. We are no exception. The U.S. Center for Disease Control and Prevention has collected very similar data. Their figures reveal insufficient sleep in most cases. Although not in every case, given that, as the neurophysiologist, pediatrician and European Sleep Medicine specialist Eduard Estivill says, we are not all the same, when it comes to how many hours’ sleep we need. “Five percent of adults are fine with sleeping for five or six hours. However, it must be the same number of hours every day. In other words, those people who sleep that long Monday through Friday and try to make it up at the weekend are mistaken, as sleep cannot be recovered – just like time, it’s lost. The vast majority of adults need between seven and a half and eight hours.

But note that some five percent of the adult population actually need nine hours of sleep; and they must be aware of this fact, as it’s not a question of being lazy, but rather that they need more hours of sleep to be fully rested.”

The question of the number of hours is more or less resolved. But there is another dilemma… knowing whether that time gives us enough rest or, in other words, if we are getting a good quality of sleep. Estivill replies: “The only indication we have as to whether we’ve slept well or not is how we feel the next day. If we have a clear head, are concentrated and eager to get things done, and not irritable, then we’ve slept well in terms of both quantity and quality.”

The most appropriate time for sleeping is between 11pm and 7am.

Indeed, we do not always get up feeling like that, even if we have been sleeping for the recommended eight hours. Because, just as important as the number of hours is the ability of a good sleep to refresh body and mind: “For example, if we are next to someone who is moving around, kicking, making noises or snoring… Even if this doesn’t wake us up, we can get the feeling that we haven’t benefited from restorative sleep. That’s why we must not only value for how long, but also how deeply we sleep, i.e. passing through all the phases: deep, superficial and REM. Only then will we have a good night’s sleep,” the director of the Sleep Clinic declares. One of the conditions for achieving this is to sleep at night. “The brain is programmed to sleep at night and be awake during the day. This is indicated by the small biological clock we all have; a group of cells, the SCN (suprachiasmatic nucleus) of the hypothalamus, which acts as a pacemaker, indicating these hours of sleep and wakefulness.

This means that, if we try to sleep during the day, it is not very refreshing.” To be specific, the most appropriate time for sleeping is between 11pm and 7am. “The first period, the initial three or four hours, consists of deep sleep, which is when we rest physically. In the second part of the night we go into the REM phase, which is when we organize our memory. Both parts are important. The first to refresh us physically, and the second intellectually.”

Some people say that having a good initial rest is enough, but that is not true. Both are equally important. Estivill goes on: “The role of sleep is basically to rest and restore our physical strength, but also to help us refresh, store and organize things in our memory. Therefore, if we are very tired we need sleep, especially deep sleep cycles. And if our work is not very physical, but rather intellectual, we need the same number of hours of sleep to feel rested the next day. That’s why we have to sleep for seven and a half or eight hours at the appropriate time. This is what will ensure we enjoy quality sleep.” This is true whether we do manual work or we are a writer.

The human brain is so well made that it even knows what the right time is for us to go to bed if we want to get a good rest. And, so we are not caught unprepared, it sends us warning signs. “This is what we call the sleep gates,” Estivill remarks. The document Healthy Sleep: Evidence and Action Guides, from the Spanish Sleep Society, explains it thus: “Quality sleep starts approximately two hours after the onset of melatonin production, which coincides with the start of the downward phase of the core body temperature and the upward phase of the distal skin temperature.” This is the perfect time to close our eyes: “The farther our sleep schedule is moved from this time window, the poorer its quality will be.”

To take advantage of that perfect moment, we should get ready to switch our brain off. As Estivill says: “Two hours before going to sleep, we should disconnect from social media, not just because of the mental activity they cause, but also because of the harmful effects of the blue light from those gadgets. What’s more, we must perform some relaxing activity that has nothing to do with our daily work. And, any issues that cannot be resolved must be deferred to the next day.” To sum up, and as Eduard Estivill’s grandmother used to say: “I don›t know why you dedicate yourself to studying sleep, when all you need to sleep well is to have a clear conscience

These indicators will tell you if your sleep is good quality

It is not always easy to know if the time we spend in bed, even when sleeping, is truly restful. These indicators published by the American National Sleep Foundation will help us find out.

  • Taking less than half an hour to fall into the land of dreams is a good sign. And it is not as common as you might think. Remember there are activities that activate your brain instead of relaxing it. 
  • Waking up at most once throughout the night or even not waking up until morning. On the contrary, interrupting the cycle of sleep on several occasions leads to feeling tired the next day.
  • Not being awake for over 20 minutes at most during the whole night indicates that you have rested well. To achieve this, say goodbye to alcohol or caffeine.
  • For 85 percent of the time spent in bed you should be sleeping. So says the National Sleep Foundation. To find out, subtract the time it takes you to fall asleep and that which you spend awake at night from the total time you spend between the sheets.