Science
Science

Common Sleep Myths

Written by: Juliann Scholl

Updated March 11, 2021

 

Sleep scientists have been hard at work learning the intricacies of why we sleep, and more and more people are realizing the importance of a good night's slumber. Unfortunately, many of us are still surrounded by persistent sleep myths that can lead to confusion regarding our sleep habits. We'll take a look at some of the most common sleep myths and discuss how to make science-backed decisions for better sleep.

1. Your Body Can Get Used to Getting Less Sleep

It's true that in some ways, we can adjust to ongoing sleep loss (1). When researchers ask sleep-deprived people to rate their mood, sleepiness, and pain tolerance, individuals initially report lower scores at first, but then report improvements the longer they go without proper sleep.

However, these subjective wellness ratings may be masking more serious negative effects. Long-term sleep deprivation is thought to cause elevated stress hormone levels and raise the risk of chronic disease (2), obesity (3), and mood disorders (4). Early research also suggests that chronic sleep deprivation may lead to lasting changes in the brain (5) that affect attention and vigilance (6).

Most adults should obtain between seven and nine hours of sleep (7) per night, and children and adolescents need even more.

2. Sleep Quality Is Not Important, As Long As You're Sleeping Enough Hours

When it comes to sleep, quality is just as important as quantity. Poor sleep quality has been linked to higher stress levels and poor dietary habits (8), and it may have effects on fitness (9), exercise recovery, decision-making, speed, and accuracy (10). Independently of sleep duration, poor sleep quality may contribute to the development of type 2 diabetes (11), heart disease (12), and other health problems.

Sleep quality can be described in subjective terms, for example by asking people if they feel well-rested. Subjectively, poor sleep quality can lead to feeling tired, grumpy, or unrefreshed (13) in the morning.

Sleep quality can also be defined objectively (14) by measuring parameters such as the time it takes to fall asleep, the number of nighttime awakenings, the total time spent awake in bed, and the time spent in each sleep stage. As we sleep, we cycle through several sleep stages. When sleep is disrupted, we may not obtain enough sleep in each sleep stage. Failing to spend enough time in certain sleep stages may have serious effects for learning, memory, and other processes (15).

3. Opening the Car Window or Turning Up the Air Conditioning Can Help With Drowsy Driving

If you find yourself opening the window to feel more alert, take it as a warning sign that you are too tired to drive. Drowsy drivers have slower reaction times (16), and they have trouble staying alert and making decisions. On the road, these effects can make it difficult to drive at a constant speed, stay in your lane, and keep an appropriate distance between vehicles.

The impairments caused by driving after 17 to 19 hours without sleep are comparable to those caused by driving with a blood alcohol content of 0.05% (17). It's estimated that at least one in 10 fatal crashes (18) are due to drowsy driving. Many of these crashes are caused by the driver falling asleep and driving off the road without attempting to brake.

In many cases, drivers don't report feeling sleepy (19), even when their driving performance worsens. Similarly, although some drivers might experience microsleeps (20) when they are drowsy, studies tracking eye movements of drowsy drivers have found that performance is not necessarily correlated to eye closure (21). The takeaway is that driving while sleepy is unsafe, even if your eyes remain open.

Opening the window, cranking the A/C, having a cup of coffee, or turning up the radio are not effective ways to drive more safely when you are feeling drowsy. The most effective way to stay safe on the road is by obtaining sufficient sleep before heading out, and taking time for breaks or alternate shifts with another driver during longer road trips.

4. It's Possible to Catch Up on Missed Sleep over the Weekend

Researchers agree it's probably possible to make up for one night of missed sleep by sleeping extra-long the next day. The problem comes when you've accumulated multiple nights of missed sleep. Every hour of sleep that you miss gets added to your "sleep debt," and studies have shown that it can take multiple nights of sleep (22) to make up for even one hour of missed sleep (23).

For people who regularly skimp on sleep during the workweek, weekends may not provide enough time to make up for all the lost sleep. Even if you do manage to sleep late on Saturday and Sunday, this tactic can throw off your sleep schedule (24) and make it harder to fall asleep on Sunday night.

Multiple nights of sleep deprivation lead to problems with attention, working memory, processing speed, and alertness. Studies on adolescents have found that even after recovery sleep, a successive week of sleep restriction causes even faster changes to these parameters, suggesting that some effects of sleep deprivation are not totally cured by recovery sleep. Irregular sleep schedules are also unhealthy in and of themselves, and have been linked to obesity and other health problems.

5. Alcohol Before Bed Will Help You Sleep

Alcohol is a depressant (25), so a nightcap may help some people fall asleep faster. In fact, at first glance, drinking alcohol before bed may appear to improve sleep quality by delaying the first rapid eye movement (REM) sleep episode and increasing the proportion of restorative slow wave sleep (26).

However, mixing alcohol and sleep generally leads to worse sleep quality in the second half of the night, marked by more nighttime awakenings and lighter sleep (27). Alcohol also reduces the total amount of REM sleep, and it may worsen snoring and sleep apnea symptoms (28).

How to Get a Better Night's Sleep

You may not be able to fool your body into thinking it's had more sleep, but there are many ways to improve both the quality and the quantity of your sleep. By prioritizing sleep and paying careful attention to your sleep hygiene, you can start to see improvements to your health and your overall well-being.

References

 

  1. https://pubmed.ncbi.nlm.nih.gov/27263430/ Accessed on March 8, 2021.
  2. https://pubmed.ncbi.nlm.nih.gov/31003950/ Accessed on March 8, 2021.
  3. https://pubmed.ncbi.nlm.nih.gov/29073414/ Accessed on March 8, 2021.
  4. https://pubmed.ncbi.nlm.nih.gov/23814343/ Accessed on March 8, 2021.
  5. https://pubmed.ncbi.nlm.nih.gov/28620347/ Accessed on March 8, 2021.
  6. https://pubmed.ncbi.nlm.nih.gov/28364507/ Accessed on March 8, 2021.
  7. https://pubmed.ncbi.nlm.nih.gov/29073412/ Accessed on March 8, 2021.
  8. https://pubmed.ncbi.nlm.nih.gov/29581959/ Accessed on March 8, 2021.
  9. https://pubmed.ncbi.nlm.nih.gov/28502838/ Accessed on March 8, 2021.
  10. https://pubmed.ncbi.nlm.nih.gov/30509635/ Accessed on March 8, 2021.
  11. https://pubmed.ncbi.nlm.nih.gov/28481337/ Accessed on March 8, 2021.
  12. https://pubmed.ncbi.nlm.nih.gov/27840384/ Accessed on March 8, 2021.
  13. https://pubmed.ncbi.nlm.nih.gov/27413553/ Accessed on March 8, 2021.
  14. https://pubmed.ncbi.nlm.nih.gov/31358470/ Accessed on March 8, 2021.
  15. https://pubmed.ncbi.nlm.nih.gov/25894546/ Accessed on March 8, 2021.
  16. https://pubmed.ncbi.nlm.nih.gov/26414989/ Accessed on March 8, 2021.
  17. https://pubmed.ncbi.nlm.nih.gov/10984335/ Accessed on March 8, 2021.
  18. https://pubmed.ncbi.nlm.nih.gov/31381433/ Accessed on March 8, 2021.
  19. https://pubmed.ncbi.nlm.nih.gov/16938511/ Accessed on March 8, 2021.
  20. https://pubmed.ncbi.nlm.nih.gov/20090864/ Accessed on March 8, 2021.
  21. https://pubmed.ncbi.nlm.nih.gov/30121104/ Accessed on March 8, 2021.
  22. https://pubmed.ncbi.nlm.nih.gov/20815182/ Accessed on March 8, 2021.
  23. https://pubmed.ncbi.nlm.nih.gov/27775095/ Accessed on March 8, 2021.
  24. https://pubmed.ncbi.nlm.nih.gov/20795887/ Accessed on March 8, 2021.
  25. https://pubmed.ncbi.nlm.nih.gov/29268093/ Accessed on March 8, 2021.
  26. https://pubmed.ncbi.nlm.nih.gov/23347102/ Accessed on March 8, 2021.
  27. https://pubmed.ncbi.nlm.nih.gov/25307588/ Accessed on March 8, 2021.
  28. https://pubmed.ncbi.nlm.nih.gov/32513091/ Accessed on March 8, 2021.