Short Sleep, Late Nights, & Nightcaps: Debunking 7 Harmful Sleep Beliefs
From nightcaps that “help” you sleep to the idea that less sleep is a sign of productivity, misinformation about sleep is everywhere—and it’s taking a toll on our well-being.
An expert-led study published in Sleep Health set out to identify the most persistent sleep myths circulating in popular culture and evaluate their accuracy. Researchers worked with a panel of sleep medicine experts to rate the “falseness” and potential public health consequences of common beliefs.
The biggest sleep myths harming your health
Out of the 20 myths reviewed, several stood out as especially problematic for long-term health.
“Many adults only need 5 hours of sleep or less.”
This is perhaps the most damaging myth of all. While some high-profile figures have touted their ability to thrive on five (or even four) hours of sleep, science doesn’t back it up. Most adults need at least 7 to 9 hours per night to function optimally. Falling short of that consistently has been linked to:
- Higher risk of heart disease and stroke
- Impaired immune function
- Mood changes and heightened risk of depression
- Metabolic issues, including weight gain and insulin resistance
Yes, there is a rare genetic mutation (the “short sleep gene”) that allows some people to function well on less. But it affects fewer than 1% of the population. For everyone else, five hours is a fast track to burnout and health problems.
“Your body can adapt to less sleep over time.”
This myth is dangerous because it feels true. After a week or two of short nights, you may no longer feel as tired, leading you to believe you’ve adapted. But under the surface, studies show your brain and body continue to decline.
Sleep restriction research has found that even when people don’t feel sleepier, their reaction times, memory, focus, and decision-making abilities keep deteriorating.
Chronic sleep debt also disrupts hormone balance, raising cortisol and reducing growth hormone and testosterone, both of which are crucial for recovery and repair.
“Being able to fall asleep anytime, anywhere means you’re a good sleeper.”
It might sound like a superpower, but it’s actually a red flag. Rapidly falling asleep in almost any situation usually signals sleep deprivation or, in some cases, an underlying sleep disorder like sleep apnea or narcolepsy.
Struggling to stay awake in quiet settings isn’t a sign of good rest; it’s your body begging for more sleep.
“It doesn’t matter what time you go to bed.”
Many people assume that as long as they log enough hours, bedtime doesn’t really matter. But science shows that when you fall asleep plays a big role in how restorative that sleep actually is.
Our bodies follow a circadian rhythm, a 24-hour internal clock that regulates everything from hormone release to metabolism. Going to bed very late, even if you still sleep 7–8 hours, can throw this rhythm off and reduce sleep quality. Research shows that people with irregular or delayed bedtimes often experience:
- Less restorative deep sleep
- More fragmented rest
- Higher risk for mood issues like depression
- Metabolic consequences, including increased diabetes risk
While some sleep is always better than none, repeatedly pushing your bedtime into the early morning hours is linked with poorer health outcomes long-term.
“Alcohol before bed helps you sleep.”
That nightcap may make you drowsy, but it doesn’t deliver quality rest. Alcohol initially acts as a sedative, helping you drift off faster, but it:
- Suppresses REM sleep, which is essential for memory and emotional regulation
- Leads to sleep fragmentation (more nighttime wakeups)
- Worsens snoring and sleep apnea by relaxing airway muscles
Over time, relying on alcohol for sleep can create a cycle of dependency while leaving you less rested.
“A sound sleeper never moves at night.”
We often imagine “good sleep” as lying perfectly still for eight hours straight, but that’s not how the body works. In reality, occasional movement is a normal and healthy part of sleep.
Studies show that people of all ages shift positions or experience brief arousals during the night. Younger adults (18–30) tend to move the least, but across the lifespan, movement is expected. Unless movements are frequent and disruptive, such as in restless legs syndrome or sleep apnea, they’re generally nothing to worry about.
Don’t equate a little tossing and turning with poor sleep. As long as you feel rested during the day, small movements at night are just part of normal sleep physiology.
“If you wake up in the middle of the night, it’s best to just stay in bed.”
It may feel natural to stay put and hope sleep comes back, but research shows this strategy often backfires. Experts rated this myth as highly false and moderately significant for public health. Why? Because lying awake in bed for too long can create a negative association between your bed and sleeplessness, fueling cycles of insomnia.
Instead, sleep specialists recommend a technique called stimulus control therapy. The idea is simple but counterintuitive:
- If you can’t fall asleep within ~20 minutes, get out of bed.
- Do something quiet and calming in dim light, like reading a book or journaling (avoid screens and bright light).
- Return to bed only when you feel drowsy again.
Don’t pressure yourself to “force” sleep while lying awake. Training your brain to associate bed with actual sleep (not tossing or worrying) helps you fall asleep faster over time.
What this means for your sleep routine
This study is a reminder that cultural sleep shortcuts, like pushing through on little rest, reaching for alcohol, or ignoring snoring, carry real health costs. But these myths are fixable with small, consistent shifts:
- Prioritize 7–9 hours as a health essential, not a luxury.
- Stick to a sleep schedule to reinforce your circadian rhythm.
- Create a sleep-friendly environment (cool, dark, quiet, screen-free).
- Add a high-quality magnesium supplement to your routine
The takeaway
Remember, quality sleep isn't a luxury; it's a fundamental pillar of health that affects everything from your immune system to your emotional well-being. By debunking these persistent myths and embracing evidence-based sleep practices, you're not just improving your nights; you're investing in better days ahead.