Is 8 Hours of Sleep a Night Too Much?

Research finding more variation in sleep needs may lead to new guidelines.

Posted Oct 03, 2014

Eight hours.

That’s the nightly sleep recommendation we hear most frequently, the highly-promoted gold standard for a healthy sleep routine.

But what if it isn’t?

I read this recent article in the Wall Street Journal with great interest, for it points to new research that suggests the eight-hour model may not be ideal one for most healthy adults. Although eight hours is the number most often associated with a full night’s sleep, sleep experts have always known that there is some degree of variation when it comes to any individual's sleep needs. Most often, the recommendation for sleep times actually comes in a range of seven-to-nine hours, depending on the individual. Indeed, the National Sleep Foundation currently recommends this seven-to-nine-hour range for healthy adults.

But a growing body of research suggests the ideal amount of sleep may in fact be at the low end of that range. A number of studies indicate that seven hours—not eight—may be the most healthful amount of nightly sleep. There’s no broad consensus about this as yet—but there’s an increasingly compelling case that, for many people, 8 hours may be more sleep than they need, even more than is healthy for them.

We hear a lot more about the dangers of too little sleep, but sleeping too much can be hazardous to your health as well. Both too little sleep and too much sleep are associated with greater mortality risks, so understanding as much as we can about the “best” amount of sleep has real importance.

The National Sleep Foundation is analyzing sleep data in preparation for the release of new guidelines. And the federal Centers for Disease Control has funded a panel to explore all manner of sleep issues, including updated recommendations for healthy sleep amounts. Both groups are expected to release their recommendations in 2015.

Those guidelines will be important, both for medical professionals and the general public. But the right amount of sleep is always going to be a personal and individual determination. The most important data in determining your sleep needs is what your body and mind tell you. Pay attention to how much (and how well) you’re sleeping at night, and to how well you feel during the day. A sufficient night of sleep should leave you feeling alert and energized through the bulk of the day, and ready for bed at roughly the same time every night.

To read your body’s need for sleep properly, it’s important to practice good sleep hygiene. That includes consistent bed times and wake times; a dark, cool, and comfortable bedtime; and quiet time away from bright light and electronics in the hour before sleep. Give yourself ample time for sleep, and create a sleep-friendly environment and routine, and your body can tell you a great deal about how much sleep you need.


Sweet Dreams,

Michael J. Breus, PhD

The Sleep Doctor™