Debunking sleep myths

Summary

Life Kit (NPR)

Episode: Debunking Sleep Myths

Host: Marielle Segarra
Guest: Rebecca Robbins (Assistant Professor of Medicine, Harvard Medical School; Sleep Scientist, Brigham and Women’s Hospital)
Date: September 15, 2025

---

Overview

This episode of Life Kit takes on some of the most persistent myths about sleep. Host Marielle Segarra sits down with sleep expert Rebecca Robbins to break down common misconceptions, explain why they linger, and provide practical, evidence-backed advice for getting more restful sleep. The conversation covers topics ranging from sleep timing and duration to bedtime habits, offering reassurance and actionable tips for anyone looking to improve their sleep quality and overall wellbeing.

---

Key Discussion Points & Insights

1. Why Sleep Matters & Why We Get It Wrong

• Sleep is crucial for brain function, immune health, and protection against diseases like heart disease and diabetes.
• There is no formal sleep education; most knowledge comes from family or culture and may not be evidence-based.
  • Quote: “In America, you learn about…nutrition or sex ed…never about sleep. So a lot of the knowledge that we have is passed down…[and] might not be evidence based.” – Rebecca Robbins [00:54]

---

2. Myth #1: “It doesn’t matter what time of day you sleep.”

• Fact: The time of sleep matters due to the circadian rhythm, which is influenced by natural light.
• The secretion of melatonin (sleep hormone) is closely tied to sunrise and sunset.
• Shift workers are at higher risk for negative health outcomes (e.g., diabetes, breast cancer), even if they use tools like blackout curtains.
• Tips for Shift Workers:
  • Wear sunglasses on the way home to reduce sun exposure.
  • Use thick blackout curtains; avoid early-morning food.
  • Try to sleep in a cool, dark environment.
• Quote: “Light plays a really integral role in our ability to sleep in a very fundamental way.” – Rebecca Robbins [03:38]
• Quote: “Unless [shift workers] are very diligent… those individuals unfortunately face a marked increase for concerning health outcomes.” – Rebecca Robbins [03:38]
  • Segment Timestamp: [03:27–06:26]

---

3. Myth #2: “Being able to fall asleep anytime, anywhere is a good thing.”

• Fact: Falling asleep instantly actually signals sleep deprivation, not good sleep health.
• Healthy sleepers take 15–20 minutes to fall asleep.
• Quote: “It’s a myth that a good sleeper…would be able to hit the pillow and fall asleep right away… That’s…a sign that you are starved for sleep.” – Rebecca Robbins [06:41]
  • Segment Timestamp: [06:26–07:34]

---

4. Myth #3: “One night of sleep deprivation will have lasting negative effects.”

• Fact: Occasional poor sleep is normal and not permanently harmful; it’s key not to dwell and to get back on track.
• Quote: “The key message here is…try to get back on track as fast as possible.” – Rebecca Robbins [07:41]
  • Segment Timestamp: [07:34–08:09]

---

5. Myth #4: “Many adults need only five or fewer hours of sleep.”

• Fact: The optimal range for adults is 7–9 hours per night.
• People who claim they thrive on less often supplement with naps.
• Long-term short sleep increases risk for health issues, while 7–9 hours is linked to best heart, brain, and longevity outcomes.
• Quote: “We do have a couple anecdotal reports… Thomas Edison…would often… take very extended naps in the afternoon.” – Rebecca Robbins [08:24]
• Quote: “There is a sweet spot… seven to nine hours. That’s where we see the most optimal health and well-being.” – Rebecca Robbins [09:06]
  • Segment Timestamp: [08:09–09:51]

---

6. Finding Your Ideal Sleep Length

• Practical tip: Add 15 minutes to your bedtime until you wake feeling refreshed without afternoon energy slumps.
• Quote: “Start tonight… see how you feel the next day…if that’s not quite enough, the next night, add another 15 minutes.” – Rebecca Robbins [10:00]
  • Segment Timestamp: [09:51–10:53]

---

7. Myth #5: “Watching TV in bed helps you relax and sleep.”

• Fact: Bed should be reserved for sleep to maintain strong “bed = sleep” mental associations.
• TV and screens emit heat and light; stressful content can spike cortisol, making sleep harder.
• Possible Exception: If a familiar show genuinely soothes you, and you have no trouble sleeping, it may not be a problem.
• Quote: “What’s happening is you’re in bed, you’re starting to associate your bed with things other than sleep…that’s…contrary to some of our key recommendations.” – Rebecca Robbins [11:05]
  • Segment Timestamp: [10:53–12:43]

---

8. Addressing “Revenge Bedtime Procrastination” and Pre-Sleep Overthinking

• Common to ruminate on negatives at bedtime due to sudden mental space.
• Advice: Focus on one or two positive things from your day; try meditation, box breathing, the 4-7-8 technique to quiet the mind.
• Designate a “worry chair” for pre-bedtime stress, keeping the bed a stress-free zone.
• Quote: “Give yourself a couple minutes before bedtime to get it all out…when you write things down, your worries, it’s like it’s not so bad after all.” – Rebecca Robbins [14:12]
  • Segment Timestamp: [12:43–14:57]

---

9. Myth #6: “Don’t exercise within 4 hours of bedtime.”

• Fact: Data does not support this; exercise generally improves sleep, and working out in the evening is fine for most people.
• Exercise helps reduce stress, improves sleep quality, and can fit wherever in your schedule.
• Quote: “We just don’t have good data to say don’t exercise close to bedtime…if that’s the only time…go for that.” – Rebecca Robbins [15:45]
  • Segment Timestamp: [15:34–16:49]

---

Memorable Moments & Notable Quotes

• On Thomas Edison’s “short sleep” myth:
  “That stinker.” – Marielle Segarra [09:02]
• On worry at bedtime:
  “I have a chair I never sit in. Maybe I’ll make it my worry chair.” – Marielle Segarra [14:49]
  “Rebrand that chair.” – Rebecca Robbins [14:53]
• On exercise:
  “If that’s when you can squeeze in your workout, do it.” – Marielle Segarra [16:58]

---

Recap & Practical Tips

[16:58–18:15]

• Aim for 7–9 hours of sleep per night.
• Sleep timing is important; exposure to natural light affects the circadian rhythm.
• Instant sleepiness means sleep deprivation; don’t worry about the occasional rough night.
• Don’t believe the “I need only five hours” myth.
• Find your personalized sleep need by gradually adjusting your routine.
• Reserve bed for sleep (some exceptions if routines work for you).
• Have an alternate place for stress or worry before bed (e.g., a “worry chair”).
• Exercise, even at night, is fine—and good for sleep.
• Keep your bedroom cool (ideally under 70°F) for less fragmented, deeper sleep.
  • “When we increase temperature, there is more sleep fragmentation…more nightmares.” – Rebecca Robbins [18:01]
• Avoid late-night screen use in bed.

---

Recommended Additional Episodes

• Dealing with Insomnia
• Revenge Bedtime Procrastination
  (Available at npr.org/lifekit)

---

This episode empowers listeners to let go of popular but harmful sleep myths, understand their body’s real needs, and try small, science-based changes for better rest—without guilt or unrealistic expectations.

Transcript

[Commercial Announcer]

This message comes from Whole Foods Market. It's stock up September at Whole Foods Market. Enjoy quick breakfasts for less with 365 by Whole Foods Market. Seasonal coffee and oatmeal. Stock up now at Whole Foods Market, in store and online.

[Marielle Segarra]

You're listening to Life Kit from npr. Hey, everybody, it's Marielle. How you sleeping these days? You getting enough shut eye? Yeah. I mean, I guess we could all be sleeping a little better, right? I feel like I do it to myself. I know you're not supposed to read the phone in bed. It's just so hard. I mean, sleep has a huge impact on our health. It helps our brains function. It supports our immune system, protects against heart disease and diabetes. And without it, we would die, though for something so important, we're never formally taught how to do it right.

[Rebecca Robbins]

In America, you learn about, you know, nutrition or sex ed in school growing up, but really never about sleep. And so a lot of the information that we have and the knowledge that we have have is passed down through our parents or our caregivers and it might not be evidence based.

[Marielle Segarra]

Rebecca Robbins is an assistant professor of medicine at Harvard Medical School and a sleep scientist at the Brigham and Women's Hospital. She and some colleagues have published research on common sleep myths, and there are a lot of them. On this episode of Life Kit, we'll walk through some of those myths and give you tips on how to get better sleep.

[Commercial Announcer]

This message comes from Charles Schwab with their original podcast Choiceology, hosted by Katie Milkman, an award winning behavioral scientist and author of the best selling book how to Change. Choiceology is a show about the psychology and economics behind people's decisions. Hear true stories from Nobel laureates, historians, authors, athletes and more about why people do the things they do. Download the latest episode and [e-mail] podcast or wherever you listen.

[Advertisement Announcer]

This message comes from LinkedIn ads. One of the hardest parts about B2B marketing is reaching the right audience. That's why you need LinkedIn ads. You can target your buyers by job title, company role, seniority and skills. All the professionals you need to reach in one place. Get a $250 credit on your campaign so you can try it yourself. Just go to LinkedIn.com results that's LinkedIn.com results. Terms and conditions apply only on LinkedIn ads. This message comes from Carvana. Why spend time wondering what your car is worth? Instantly track its value on Carvana Value Tracker, answer a few quick questions and stay up to speed on your car's value. Track your car's [e-mail] this message comes from Ethos. Discover the modern way to get life insurance all online. Protect your family's future against the unexpected in minutes, not months. With Ethos, you could get up to 3 million in coverage without a medical exam. Just answer a few health questions. Some policies are as low as $2 a day billed monthly. Get your free [e-mail] NPR that's ethos.com NPR Application times may vary.

[Marielle Segarra]

Rates may vary okay, Rebecca, let's get into some of the myths. One that stuck out to us is that it doesn't matter what time of day you sleep.

[Rebecca Robbins]

Now this is a myth because unfortunately, it does matter. The circadian rhythm, this internal circuitry that guides the secretion of the essential sleep hormone melatonin. That circuitry is significantly influenced by natural sleep. Sunlight in our environment. We are as human beings built to respond to the light in our environment. When the sun comes up, that sunshine that we're able to get by going outside stops the floodgates of melatonin, the sleep hormone, and switches the on phase of our circadian rhythm. And then conversely, going into a cool, ideally cool, dark environment is what allows for the secretion of melatonin. So light plays a really integral role in our ability to sleep in a very fundamental way. And now because of the importance of light, individuals who are working on maybe overnight schedules or shift schedules that are outside the typical 9 to 5pm window that would allow us to align our sleep with the patterns of light and darkness in our environment. Unless they are very diligent and very careful about the exposure they get to natural sunlight, those individuals unfortunately face a marked increase for concerning health outcomes.

[Marielle Segarra]

What kinds of health outcomes are we talking about?

[Rebecca Robbins]

Unfortunately, some of the research is shown in physicians and in nurses who are commonly working on such schedules. There is an increase for outcomes such as diabetes and breast cancer and others that are concerning. And sleep is implicated in that equation is one of the factors that contributes to that increased risk. So unfortunately, those individuals really struggle to get good sleep and consistent and consolidated sleep that supports their health and well being.

[Marielle Segarra]

So it sounds like it's not enough if you're, you know, on that schedule to have blackout curtains or something like that when you're trying to sleep in the middle of the day because you've just been exposed to light and your body still knows that it's the daytime.

[Rebecca Robbins]

If you're very diligent, if you have very thick blackout curtains and are very careful, some of the recommendations we Give shift workers are to, for instance, a nurse working in the hospital. On the drive home, wear sunglasses to kind of trick your brain that it's not sunrise around you. Trying to avoid light in your work environment as you approach the end of your shift. Avoiding food also in those early morning hours before the sun rises. Trying to get home and get consolidated sleep. But there are a host of other challenges, because if you're a shift worker and maybe have a family, you likely are having to constantly shift your schedule back and forth between their work schedule and their personal schedule.

[Marielle Segarra]

It's so hard because it can feel like when you're on one of those jobs, like there is no. There is no escape from it. What about this one? Being able to fall asleep anytime, anywhere is a good thing.

[Rebecca Robbins]

We hear this often. People say, oh, so and so is able to fall right asleep. I'm so jealous they're such a good sleeper. But this is a myth because it takes a well rested, healthy person, even about 15 or 20 minutes or maybe a little bit longer to fall asleep. It's a myth that a good sleeper would be able to hit the pillow and fall asleep right away. And this is because sleep really is a process, and falling asleep does take a little bit of time. But it is a myth that falling asleep is a good thing when it's immediate because that's instead really a sign that you are starved for sleep. And so, same thing. If you were starved for food and you sat down at any opportunity and had a huge meal and ate variety voraciously, then that would probably be a sign that you're not getting enough nutrition. So the same thing with sleep.

[Marielle Segarra]

Okay, next myth. That one night of sleep deprivation will have lasting negative effects.

[Rebecca Robbins]

This is a myth because it's not going to be perfect every night. And so every now and then we might struggle. And that's because sleep is a consequence of the human condition. So if we experience some stress during the day and our sleep suffers that night, the key message here is that that can happen from time to time. But not to beat yourself up too much, and instead try to get back on track as fast as possible.

[Marielle Segarra]

Okay, well, what about this one? Many adults need only five or few hours of sleep for general health. I've heard a lot of people say this, like, oh, I just don't need to sleep that much. It's fine. I sleep. I sleep four hours a night, and I feel great.

[Rebecca Robbins]

And unfortunately, in our society, people often brag about that. So I think we have a long way to go to really position Sleep, you know, in our society as a part of daytime performance and success, unfortunately, it has a little bit of a bad rap that people who are maybe meeting their sleep need or look well rested or lazy. But indeed, this is a myth. We do have a couple anecdotal reports. Thomas Edison, for instance, would brag about only needing four hours of sleep. What he forgot to mention is that he had a bed in his office and he would often. There are reports of him taking very extended naps in the afternoon.

[Marielle Segarra]

Wow, that stinker.

[Rebecca Robbins]

And so one of the things that is often not talked about is the compensatory naps that individuals who are not getting enough sleep will likely be relying on naps. If we look at the hard health outcomes and we look at how long people are sleeping, there is a sweet spot, and that is seven to nine hours. And that's where we see the most optimal health and well being. Improved heart health, cardiometabolic outcomes, long longevity, brain health into our older years are all in those that are sleeping as much as they can as many nights of the week as possible, in that range of seven to nine hours and hitting that need again as many nights of the week as possible.

[Marielle Segarra]

Okay, well, if you are looking at this range of 7 to 9 hours, how do you know where you fall? What, like, what is your sweet spot.

[Rebecca Robbins]

Depending on where you are today? If you were maybe sleeping six hours, the best way to try to get into the recommended range and then figure out where you are when it comes to your personal sleep need is to start Tonight, add just 15 minutes to your overall sleep routine, starting the process to bed a little bit earlier, unplugging from screens, starting your bedtime routine, and making sure that you're in bed in between the sheets about 15 minutes earlier than usual, and then see how you feel the next day. If that brings you to six hours and 15 minutes, wonderful. And if you're able to wake up and really feel refreshed and also have energy through the day and not really be reaching for coffee or energy drinks in the afternoon, then you're inching closer to your sleep need. And then if that's not quite enough, however, the next night, add another 15 minutes.

[Marielle Segarra]

Well, along the lines of sleep sleep hygiene, here's another myth that watching TV in bed is a good way to relax before you go to sleep.

[Rebecca Robbins]

Now, here's the thing with this myth. Yes, it is a myth. It is not something we're going to recommend because what's happening is you're in bed, you're starting to Associate your bed with things other than sleep, which is actually contrary to some of our key recommendations. We often say keeps bed for sleep. So that's the first thing that we're doing. Things in bed that are non sleep related. But then you're also maybe looking at a television screen, or worse, a laptop screen. If you have. If that's the only screen you have to watch a show on, then maybe that's on your lap, and that might be something that's emitting heat, which isn't ideal. We really want to keep the body cool as we approach bedtime. And then if what you're watching is stressful, that could also cause your cortisol to spike and hinder your ability to fall asleep. So watching TV is not something that we would recommend before bed. There might be, you know, one exception here, and that is we hear often that some people have routines they fall asleep to. Maybe they have an episode of Friends or Seinfeld, and it's on a timer and it will go off after 20 or 30 minutes. But there's something about the characters in a certain show that is soothing to some people. So the only exception to this myth is if it's not broken, don't worry about fixing it. So if you find falling asleep to a soothing show is relaxing, wonderful. God bless you, Carry on. But if you find that you're watching the nightly news and it's stressful and you're struggling to power down, then this might be something to cut out.

[Marielle Segarra]

Well, what about as an alternative? Just like laying up, sort of staring at the ceiling, mentally flipping through the highlight reel of every mistake you've ever made.

[Rebecca Robbins]

Unfortunately, this is common before bedtime. It's wild. I feel like that's my personal favorite. Right. Well, I think you're not alone. I think this happens to a lot of people because in our modern lives, we're consuming content and we're responding to emails, and you get into this mode in our workday, and then suddenly that all comes to a screeching halt at night, and we're supposed to crawl into bed and go right to sleep. So I think one very simple strategy that we could all do and really benefit from is really focusing on one or two really good things that happened in your day, whether that was something that a colleague said or someone that passed you on the metro that helped you with a bag, something that was really positive and focusing on that. There are also a series of meditation and relaxation strategies, and there are lots of very specific exercises. Box breathing. The 4 7, 8 technique. A lot of these are really powerful for helping you find peace in the moment, which is again, what we all need before bed. So building in one of those strategies could be a really great way to overcome that challenge before bedtime.

[Marielle Segarra]

I like to use the moments before sleep to completely rethink my relationships and.

[Rebecca Robbins]

You know, touch base on all the stressful things that happened.

[Marielle Segarra]

Yeah. Think about what I've done.

[Rebecca Robbins]

Well, Marilyn 1, I hear you right, and sometimes you need space for that. But like one way is to maybe just try to not do that in bed. If I were to make one small suggestion, because if we're doing that in bed, then we're starting to associate stress and worry and negative things with bed and sleep. And so maybe have a. This is. I know it sounds cheesy, but sometimes we recommend having a concentrated worry time. Give yourself a couple minutes before bedtime to get it all out and maybe you're writing it down or. Cause sometimes when it just is lingering in your mind, it just is so much worse. But when you write things down, your worries, it's like it's not so bad after all.

[Marielle Segarra]

Yeah, it occurs to me I have a chair I never sit in. Maybe I'll make it my worry chair.

[Rebecca Robbins]

I love it. Rebrand that chair.

[Marielle Segarra]

We'll have more Life Kit after the break.

[Commercial Announcer]

Support for this podcast and the following message come from Strawberry Me. Be honest, are you happy with your job? Are you stuck in a job you've outgrown or never wanted in the first place? Are your reasons for staying really just excuses for not leaving? Let a career coach from Strawberry Me help you get unstuck. Discover the benefits of having a dedicated career coach in your corner and claim a special offer at Strawberry Me.

[Marielle Segarra]

Okay, one more that we thought was interesting, that exercising within four hours of bedtime will disturb your sleep. And that's a myth.

[Rebecca Robbins]

This is a myth because we've really said for many, many years in sleep, avoid exercise close to bedtime. But we actually don't have any good data to back that up. And I love this because there's so many benefits of exercise, not only from our health and well being, our mental health, our physical health, but also our sleep health. Those that exercise get better sleep, they report deeper sleep, more restorative sleep, better sleep quality, less sleep fragmentation. Basically, exercise releases endorphins, which are mood elevators. And that can help with the number one cause of sleep difficulties, which is stress. And so making time for exercise is critical as many days of the week as possible, breaking a sweat. And so this is a myth because we just don't have good data to say don't exercise close to bedtime. And so if that's the only time that you can get a workout in, then by all means carry on and go for that. I do like this because it really kind of empowers people that maybe only have time to work out right before bedtime or in the evening hours. It gives them license to do so.

[Marielle Segarra]

Okay, well, thank you so much. I have some things to try. I'm excited.

[Rebecca Robbins]

Wonderful.

[Marielle Segarra]

All right, time for a recap, sleepyheads. Adults should be getting seven to nine hours of sleep a night. You may think you can function on less, but research shows that's associated with a higher risk of adverse health outcomes. It does matter what time of day you sleep, which is tough news for shift workers. The people who stay up nights making sure we have clean water and medical care. If this is you, there are things you can do to make the situation a little better. Blackout curtains, wearing sunglasses on the way home in the morning. A lot of this has to do with how much light you're exposed to. Being able to fall asleep anywhere, anytime is not necessarily a good thing. It might just be a sign that you're sleep deprived. One night of bad sleep is not going to have long term negative effects. Now this one surprised me. It is okay to exercise before bed. Maybe don't get too intense about it, but if that's when you can squeeze in your workout, do it. Another tip Robin shared with me. If you're having trouble sleeping, that may be because your bedroom is too warm. Make sure it's cool, like under 70 degrees.

[Rebecca Robbins]

Some people do prefer a warmer environment, but we do have data to show that when we increase temperature, there is more sleep fragmentation. So more tossing and turning, more disruption from sleep, and more nightmares.

[Marielle Segarra]

And as always, try not to look at your phone in bed. I know it's hard, but that phone will be waiting for you in the morning. Promise for more Life Kit check out our other episodes. We have one about dealing with insomnia and another about revenge bedtime procrastination. You can find [e-mail] LifeKit and if you love Life Kit and want even more, subscribe to our [e-mail] LifeKitnewsletter Also, we'd love to hear from you. So if you have episode ideas or feedback you want to share, email [e-mail] this episode of Life Kit was produced by Claire Marie Schneider. Our visuals editor is Beck Harlan and our digital editor is Malika Garib. Megan Keane is our senior supervising editor and Beth Donovan is our executive producer. Our production team also includes Andy Taegle, Margaret Serino and Sylvie Douglas. Engineering support comes from Simon Laszlo Jansen. I'm Mariel Segarra. Thanks for listening.

[Advertisement Announcer]

This message comes from NPR sponsor Shopify, the commerce platform behind millions of businesses around the world and 10% of all E commerce in the US get started with your own design studio. Sign up for your $1 per month [e-mail] NPR this message comes from NPR sponsor Viori. Featuring the core short receive 20% off your first purchase on any U.S. orders over $75 and free [e-mail] NPR exclusions apply. Visit the website for full terms and conditions.

[Commercial Announcer]

This message comes from Mint Mobile. If you're tired of spending hundreds on big wireless bills, bogus fees and free perks, Mint Mobile might be right for you. With plans starting from 15 bucks a month. Shop plans today at mintmobile. Com Switch upfront payment of 45 dollars for 3 month 5 gigabyte plan required, new customer offer for first 3 months only, then full price plan options available, taxes and fees extra. See Mint Mobile for details.