7 hours

Not a surprise so much as pretty good science. Also, 7 other things worth your time.

I’m going to share a study about sleep—supposedly the largest real-world sleep study in history.

It seems appropriate to talk about today, both because nearly every person I talked with on Sunday was sleep-deprived after turning the clocks ahead—and frankly, because I’m pretty darn tired myself.

Researchers at the Brain and Mind Institute at Western University in Canada say they asked 44,000 people to track their sleep over a three-day period, and then to take a series of cognitive and neurological tests. 

That’s a big sample size, they say, and they were also quite proud of having focused their research on real-life conditions, as opposed to the lab. Neuroscientist Adrian M. Owen, who led the study, explained:

"Obviously there have been many smaller studies of people in laboratories. But we wanted to find out what sleep is like in the real world. How do real people sleep? How much sleep do they get and what effect is it having on their brain?"

After synthesizing the data from a total of more than 132,000 person-nights of sleep, they were able to graph length of sleep against test performance. Owen's research associate, Conor Wild, explained the results:

"The optimum amount of sleep to keep your brain performing at its best was between seven to eight hours every single night.”

I know that minimum amount of sleep won’t be a surprise; it’s what doctors, popular press, and probably your mom have told you for years. But, it’s nice to see it documented in some quantifiable work.

Plus, there was another finding, Wild added: Those who exceeded the maximum suggested sleep time "were equally as impaired as those who slept too little."

As for why? That's a topic for further study, informed by the massive trove of data they've now collected.

Now, I suspect for most of us, the idea of getting "too much sleep" is probably a dream. According to Gallup, the average for U.S. adults is about 6.8 hours per night, so not too far off the minimum—although about 40 percent say they rarely get more than six hours.

There certainly have been times in my life when I’ve sacrificed sleep in order to take care of my family and work to build things. I’ll bet you might be able to say the same.

Because as my colleague Jessica Stillman has written over on Inc.com (one of my favorite insights, although kind of a depressing one in a way), if you have five priorities—

  • work,

  • sleep,

  • family,

  • fitness, and

  • friends

—you generally get to pick three. For many of us, sleep suffers.

Speaking of which: Tomorrow's another day, and as I write this, it will be here in fewer than seven hours. Do as I say, in other words, not as I do.

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7 other things worth your time


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