Getting eight hours of sleep isn’t what makes sleep “refreshing,” science says so
We know that we spend a third of our life sleeping. What we leave out – and do not consider – is the assessment of the quality of one’s sleep. If you’re always tired, the question to ask isn’t “Maybe I didn’t get enough sleep?” but “ How did I sleep?”. Unfortunately, unless we participate in a sleep study, we have no real understanding of the quality of our sleep, so it is difficult to answer this question comprehensively. Dr. William McCall, who heads the Department of Psychiatry and Health Behavior of the Medical College of Georgia at Augusta University explained that the only element to consider, in order to be able to say that we have rested adequately, is not the duration of sleep but the combination of “durability and efficiency”.
To measure efficiency, you need to evaluate how you feel the next day . “If you feel good during the day even if you got less than eight hours of sleep, then your sleep is working well,” said the professor. “But if you are often or always tired during the day, this could indicate a deficit in sleep duration or efficiency. The signs to watch out for are: struggling to get out of bed in the morning, feeling sluggish, unfocused or irritable in the afternoon. These can also be symptoms of other health issues, which is all the more reason to understand what’s behind chronic daytime fatigue and seek medical attention if you can’t reduce or eliminate symptoms.”
According to experts, most adults need between seven and eight hours of sleep a night. Some people manage to sleep less , partly for genetic reasons, but recent research (such as this one published in Nature aging ) suggests that less than seven hours, and in particular less than six, not only leave you tired, but also increase the risk of numerous physical and mental health problems.
How does sleep work?
Sleep occurs in several repeating cycles of four stages ranging from light to deep sleep. During deep sleep, hormones and other chemicals are released to repair and rejuvenate the body’s organs and tissues, while a waste collection system of the Central Nervous System, called the glymphatic system , clears the brain of misfolded proteins and other substances. garbage and toxins accumulated during the day. During REM sleep, the rapid eye movement phase in which most dreams occur, short-term memories are converted to long-term memory and bad thoughts and negative emotions are addressed and even pushed away.
If sleep is interrupted or disturbed during the night, even if we don’t realize it, we deprive the brain and body of these rejuvenating processes.
However, time spent asleep accounts for about 85 percent of good sleep efficiency, McCall and his colleagues noted in a study published earlier this year in the journal Scientific Reports . This means that, to get seven hours of effective and truly quality sleep, considering all sleep cycles, you need (a little) more than eight hours in bed.
Do you use the smartwatch that tells you how you slept?
The length of time spent in each stage can only be accurately measured by studies and centers that evaluate sleep quality, with devices that monitor brain waves, body temperature and other indicators of deep and REM sleep. There are sleep trackers on the market (for example smart watches) which, however, do not return accurate data in terms of distinguishing between light sleep, deep sleep and REM sleep. Another study suggests, with some irony, that obsession for the collection of these same data can cause stress that is bad for sleep. “Unfortunately, excessive self-monitoring and self-monitoring of sleep with a sleep-tracking device can make the situation worse, just as excessive self-monitoring of weight can be found in people with eating disorders,” McCall said. “It’s important to have a general idea of your sleep, but you don’t need to check in daily for long periods of time.”
There are many tactics that help people fall asleep faster and sleep more efficiently, resulting in improved overall sleep quality. A good strategy for sleep it comes down to routine, constant commitment to healthy habits, or, as McCall and other experts suggest: choosing a time to go to bed and, possibly, respecting it every day; spend at least two hours a day outdoors, daylight helps regulate the biorhythm and optimize the sleep-wake cycle; avoid caffeine after the early afternoon and, if not needed, eliminate it; get at least 20 to 30 minutes of physical activity daily, such as brisk walking, yoga, weight lifting, or any other movement that gets the blood pumping. If you take a nap, do it before late afternoon and limit it to 30 minutes or less. Avoid engaging in stressful late-night activities, such as reading or watching disturbing news or social media posts, discussing politics, or checking work emails. Turn off or dim all lights in the house in the last hour or two before bed. Waking up at the same time every day. Maybe they look like obvious , but reading the list, can we actually admit that we follow all these suggestions to the letter? If the answer is no and during the day, even if you slept 8 hours, you feel more tired than how you went to sleep, you could try to use this vade mecum word for word and who knows, maybe even sleeping 7 hours, you will have a truly restful sleep.