Sleep when you're dead

A study about getting too much sleep, which frankly seems like a good problem. Also, 7 other things worth your time.

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Getting enough sleep is one of the easiest things you can do to boost your memory, improve your mood, and positively affect many other parts of your life. It's truly a magic elixir.

But science now proves you can get too much of a good thing. Because a massive study of 116,632 people's sleep habits shows an unmistakable link between getting too much sleep, and dying prematurely.

Writing in the European Heart Journal, Chuangshi Wang of McMaster University in Canada examined the associations between people's (a) total sleep time and frequency of afternoon naps and (b) total deaths and major cardiovascular events.

The findings:

  • People who slept between eight nine hours each night had a roughly 5 percent greater risk of developing cardiovascular disease or dying early, compared to people who slept only six hours per night.

  • People who slept between nine and 10 hours per night had a 17 percent greater risk of the same conditions or early death than the six-hour-per-night sleepers.

  • Those who slept more than 10 hours a night had a stunning 41 percent higher rate of cardiovascular disease or dying early.

There are three big caveats to note here. The first is our old friend, correlation versus causation.

Specifically, this study suggests that people who sleep longer are more likely to die early -- but it doesn't necessarily suggest that they die earlier because they sleep more.

It's possible for example that people who develop cardiovascular disease are simply heavier sleepers and are more likely to die early. One doesn't have to cause the other. Similarly, it might make sense that people who had nascent or developing health issues would be more likely to take daytime naps.

Second, and this will allow many of us to breathe a sigh of relief, the link between daytime napping and increased rate of death only mattered in people who were sleeping more than six hours a night. 

So if you're like me, and you struggle to get enough sleep at night with all your commitments but occasionally crash for an hour during the day, you're good.

Finally, it should also be noted that in general, a median of 7.8 years passed between the first measurement of people's sleep, and the follow up report that noted whether they were healthy, or had developed diseases or even passed away.

Based on that, it doesn't seem that this turned out to be a study of mostly people who were sick to begin with, for example. In fact, the researchers said they controlled for age, BMI, smoking and alcohol use, and lots of other health and behavioral data.

Across the board, of the just over 116,000 people studied, 4,381 were deceased by the end of the study, and 4,365 had major cardiovascular events. So just over 7.5 percent combined.

The takeaways? Well, the good news is that this should ultimately make our sleep targets more reasonable, especially for busy entrepreneurs and other people. 

"Get enough sleep -- that is, six to eight hours a day," Wang told the New York Times when it reported on this. "But if you sleep more than nine hours a day, you may want to visit a doctor to check your overall health." 


There are 7 days left until the U.S. presidential election. As of last night, 63,601,743 ballots have already been returned.* (Interesting data point: In the 1980 Reagan landslide election, there were 86,509,678 total votes. Of course, our population is about 45% bigger now.)

*I changed the wording here from previous days. This number in red is actually the (a) number of votes that have been cast in person, plus (b) the number of mail ballots that actually have been received. As we’ll see below, if you vote by mail now—it’s probably too late, and your vote might not be counted. Vote in person or return your ballot to a drop-off point if you can!


7 other things worth your time

  • As mentioned above… Planning to vote by mail? It’s probably too late. There’s a very good chance your ballot won’t be delivered on time and your vote won’t count, according to a study in The Wall Street Journal. At this point, try a drop-off box if you can, or else vote in person. (The Wall Street Journal)

  • The superintendent of Virginia Military Academy resigned, a week after the state’s governor ordered an investigation into a culture of racism at the academy. (Richmond.com)

  • The city of El Paso, Texas implemented a two-week stay-at-home order, with fines of $500, due to hospitals at capacity with Covid-19 patients. Officials said essential workers can go to and from work, and it’s OK to leave home to vote. Also, 1,000 Texas National Guard troops have been ordered to the state’s cities for the election. (Texas Tribune, MySanAntonio.com)

  • Delta Air Lines says it has now banned 460 passengers from its flights for refusing to wear masks. Other airlines have their own banned lists, but they don’t share information with each other. (CNN)

  • Justice Amy Coney Barrett was sworn in as the newest associate justice of the U.S. Supreme Court after a 52-48 vote, with zero bipartisan support, just 38 days after the death of Ruth Bader Ginsburg, and only eight days before the 2020 election. (NPR)

  • Complete change of gears here: Every year, KFC sells fried chicken-scented fireplace logs and they sell out FAST. This year, Walmart just announced it signed a deal to sell them exclusively. (Fox Business)

  • A new study says going for an “awe walk,” which is basically a virgorous walk, outside, in an environment that leaves you feeling “awe” (aka, “the feeling of smallness and wonder you experience when you stand before something vastly bigger than you), reduces stress and can keep your brain young. My colleague Jessica Stillman wrote about the study. (Inc.com)

Finally, a bonus if you will: I just found this kind of funny and apt:


The sleep thing: I’ve written about this study before, at Inc.com. If you liked this post, and you’re not yet a subscriber, what are you waiting for? Please sign up for the daily Understandably.com email newsletter, with thousands and thousands of 5-star ratings from happy readers. You can also just send an email to signup@understandably.com.

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