IE 11 is not supported. For an optimal experience visit our site on another browser.

How long is too long to nap? Sleep doctor shares when it can hurt your health

Can snoozing on the couch really help you stay healthy and live longer?

To nap or not to nap? That is a question a lot of us find ourselves asking regularly. Modern life makes it feel impossible to get in enough sleep sometimes. Luckily, modern science has some answers. Dr. Carol Ash, a sleep expert at RWJ Barnabas Health in New York, joined TODAY in a segment aired on Feb. 23 to answer a few of our burning questions about sleep. Some of her answers may surprise you.

Losing quality sleep impacts your life expectancy — a lot

According to a new study being presented at the American College of Cardiology’s Annual Scientific Session together with the World Congress of Cardiology, the quality of the sleep you get can significantly impact your life expectancy — perhaps more so than the quantity.

Researchers involved with the study looked at the health data of 172,321 in the U.S. — which makes it the largest sleep study of its kind. What scientists found was that the life expectancy of people who got high quality sleep — according to five factors — was 4.7 years greater for men and 2.4 years greater for women when compared with individuals who had poorer sleep quality.

On its own, the fact that sleep makes a difference in how long you live is jarring, but not totally unexpected because this study confirms sleep research done over the past few decades. We all know sleep is important. But what about folks who struggle to hit their sleep goals? What does that mean for health and will napping help?

Will napping help?

The short answer is yes, but there are a few caveats. Napping can help you stay healthy, but there's a sweet spot when it comes to how long your naps should be.

"Naps are good, but you want to keep it no more than 40 minutes," Ash said on TODAY.

Unfortunately, making sure you get enough quality sleep can't be boiled down to a simple math equation, Sheinelle Jones pointed out. "There are a lot of people who will do four hours and then two and think, 'Well, I got six hours total today." Those folks are in for a bit of a rude awakening.

"The nature of sleep is you want to do it [consecutively]," Ash said. But Ash also understands that not everyone is able to hit that sleep sweet spot. And she was quick to point out that naps can help. "Obviously we’re all busy so when you don’t do that, you offset it with naps," Ash said on TODAY. Exercising and having other healthy habits will also help, Ash added.

How do you know if you're getting high quality sleep?

If you're wondering what, exactly, determines whether you're getting high quality sleep, Ash said that people who get high quality sleep have these five things in common:

  • They get 7-8 hours of sleep a night.
  • They have no difficulty falling asleep.
  • They have no trouble staying asleep.
  • They don't take sleep medications.
  • They wake up feeling well-rested.

Many of us can't check all those boxes, but Ash said that hitting as many as possible is better than none at all.

How will getting good sleep impact your health?

The study found three important findings about how sleep affects your life expectancy. Getting good quality sleep:

  • Reduces the risk of death for any reason by 30%.
  • Reduces risk of death from cardiovascular disease 24%.
  • Reduces risk of death from cancer 19%.

The bottom line

Don't be alarmed if you're not meeting all five of the quality sleep factors. Some sleep is better than none at all. And, like Ash said, napping can help as long as you don't try to make it a substitute for sleeping at night.

"There’s benefit from making sure that you have at least one or two of the sleep factors on lockdown and take naps on the weekends, Ash told TODAY. So you can think of a 40-minute nap as a sort of health supplement and, let's be honest, napping is much more appealing than some of the trendy health hacks out there.