Eight hours of sleep. Six hours of sleep. Seven hours of sleep. It seems like every year we see a study that claims that some amount of hours is better than another. The Wall Street Journal collects together a few studies that show data suggests that seven hours might be the sweet spot these days.
The Wall Street Journal looked at a few different studies. Here's a summation of just a few of them:
"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...
...Daniel F. Kripke, an emeritus professor of psychiatry at the University of California San Diego, tracked over a six-year period data on 1.1 million people who participated in a large cancer study. People who reported they slept 6.5 to 7.4 hours had a lower mortality rate than those with shorter or longer sleep. The study, published in the Archives of General Psychiatry in 2002, controlled for 32 health factors, including medications...
...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.
That said, as with most of these kinds of things, it's not an exact science. But you can figure out your own perfect sleep schedule if you're willing to take the time to experiment on yourself:
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.
As we've pointed out before, it's about figuring out what works for you. Experts currently recommend anywhere between six and nine hours of sleep, so, for now, you'll want to shoot for somewhere in that range, preferably closer to the seven-hour mark.
Why Seven Hours of Sleep Might Be Better Than Eight [The Wall Street Journal]