July 22, 2014 Leave a comment
So, we’ve been hearing for years about how 8 hours of sleep (or maybe 7-9) is best. Now, a lot of researchers are actually arguing that about 7 is truly optimal and that it goes downhill from there. WSJ:
Several sleep studies have found that seven hours is the optimal amount of sleep—not eight, as was long believed—when it comes to certain cognitive and health markers, although many doctors question that conclusion.
Other recent research has shown that skimping on a full night’s sleep, even by 20 minutes, impairs performance and memory the next day. And getting too much sleep—not just too little of it—is associated with health problems including diabetes, obesity and cardiovascular disease and with higher rates of death, studies show.
“The lowest mortality and morbidity is with seven hours,” said Shawn Youngstedt, a professor in the College of Nursing and Health Innovation at Arizona State University Phoenix. “Eight hours or more has consistently been shown to be hazardous,” says Dr. Youngstedt, who researches the effects of oversleeping…
Getting the right amount of sleep is important in being alert the next day, and several recent studies have found an association between getting seven hours of sleep and optimal cognitive performance.
A study in the journal Frontiers in Human Neuroscience last year used data from users of the cognitive-training website Lumosity. Researchers looked at the self-reported sleeping habits of about 160,000 users who took spatial-memory and matching tests and about 127,000 users who took an arithmetic test. They found that cognitive performance increased as people got more sleep, reaching a peak at seven hours before starting to decline.
After seven hours, “increasing sleep was not any more beneficial,” said Murali Doraiswamy, a professor of psychiatry at Duke University Medical Center in Durham…
Now, here’s the part I simply don’t buy…
Experts say people should be able to figure out their optimal amount of sleep in a trial of three days to a week, ideally while on vacation. Don’t use an alarm clock. Go to sleep when you get tired. Avoid too much caffeine or alcohol. And stay off electronic devices a couple of hours before going to bed. During the trial, track your sleep with a diary or a device that records your actual sleep time. If you feel refreshed and awake during the day, you’ve probably discovered your optimal sleep time.
I don’t know about you, but left to my own devices, I never wake up after only 7 hours feeling nicely refreshed. It is always 8+ if not 9. And anecdotally, I don’t think I’m particularly unusual in that. That said, I used to always aim for 8, but after Sarah was born I found I was seemingly getting by just fine with 7, so that’s been my minimum goal ever since. Maybe my cognitive performance suffers on those days I get to sleep in, but it sure feels good (and heck, I’ve got some cognitive performance to spare :-) ).
Meanwhile, Wired writes about “sleep drunkenness”
Oversleeping feels so much like a hangover that scientists call it sleep drunkenness. But, unlike the brute force neurological damage caused by alcohol, your misguided attempt to stock up on rest makes you feel sluggish by confusing the part of your brain that controls your body’s daily cycle…
When you sleep too much, you’re throwing off that biological clock, and it starts telling the cells a different story than what they’re actually experiencing, inducing a sense of fatigue. You might be crawling out of bed at 11am, but your cells started using their energy cycle at seven. This is similar to how jet lag works…
If everything’s just fine with your sleep zone but you still can’t get under the eight hour mark, you might need to go see a doctor. It could be a symptom of narcolepsy, which makes it hard for your body to regulate fatigue and makes you sleep in more.
Oh, give me a break. Now they want people who sleep 8.5 hours a night to actually go their doctor over the issue?! Just not buying it.
And, while I’m at it, I’m going to combine what was going to be a separate post about kids and sleep. Basically, we need to have our children appreciate the value of sleep:
We tell children why it’s important to eat their vegetables. We tell them why they need to get outside and run around. But how often do we parents tell children why it’s important to sleep? “Time for bed!” is usually the end of it, or maybe “You’ll be tired tomorrow.” No wonder children regard sleep as vaguely punitive, an enforced period of dull isolation in a darkened room. But of course sleep is so much more, and maybe we ought to try telling children that…
There is evidence that educating children about the importance of sleep leads them to sleep more. Two studies conducted with seventh graders, for example, found that after participating in a “sleep smart” program, they went to bed earlier and slept longer on weeknights.
I was particularly intrigued by this because of what I’ve seen in my oldest son. Years ago I told him about the research finding that chronically sleeping too little can impact the cognitive performance of children by as much as two grade levels. I told him that not enough sleep might cause his 5th grade brain to function like that of a 3rd grader. Damn, we he sold on it. I never have to tell him to go to bed earlier. In fact, on occasion I have to convince him that it is okay to stay up late on occasion for special events. I love the degree that he has internalized the importance of good sleep. I guess now I just have to worry about him wanting more than 7 hours when he is an adult :-).