4 common sleep myths, debunked

Sleep is mysterious. All of us lay down every night and proceed to be completely unaware of what’s happening in the waking world around us as we snooze. It’s an absurd state of affairs.

It shouldn’t be surprising, then, that there are all kinds of myths about sleep. We have inaccurate ideas about what prevents us from sleeping, what helps us sleep, and what happens while we’re sleeping. Here are four common sleep myths, refuted by scientific studies. 

Exercise before bed is fine, actually

Some people believe you shouldn’t work out right before bed if you want a good night’s sleep. Others think you shouldn’t work out within a few hours of going to sleep. The logic seems to be that getting your heart rate up could make slowing down to fall asleep more difficult. 

Scientific research doesn’t back this at all, however. A paper breaking down common sleep myths published in Sleep Health, the journal of the National Sleep Foundation—written by Rebecca Robbins of NYU Langone Health and several other collaborators—states definitively that there’s no data backing up the idea that you need a buffer between working out and sleeping. “According to survey data from US adults, nighttime exercise was not associated with sleep disturbance for the majority of individuals,” the paper states. “Other experimental evidence shows no impairment in sleep following vigorous nighttime exercise.” 

There are reasons you might not want to work out right before bed, of course, but sleep isn’t one of them. Work out in the evening if that’s what works for you 

Alcohol doesn’t help you sleep

You might think a bit of booze before going to be—a nightcap—helps you fall asleep. Even if that’s true, though, alcohol means the sleep will leave you feeling less refreshed according to sleep medicine expert Dr. Nancy Foldvary-Schaefer of the Cleveland Clinic. 

“Alcohol in your system leads to your sleep being fragmented, meaning your brain briefly wakes up and interrupts your sleep cycle over and over,” she said on the clinic’s website. “Every ‘awakening’ can send you back to the light sleep stage, and cuts down on your REM sleep.”

Robbins et al come to the same conclusion in their paper. “The literature on sleep and alcohol shows alcohol consumed close to bedtime reduces sleep latency, but subsequently causes sleep disturbances in the second half of the night,” the experts found. “Across a number of different studies and doses, overall alcohol has a negative overall impact on sleep, delaying the onset of REM sleep.” 

You might enjoy a nip before bed, sure, but research suggests it’s not helping you sleep better. 

Remembering dreams doesn’t mean you slept poorly (or well)

There are a couple of contradictory myths at work here. Some people say that remembering dreams means you didn’t sleep well. The logic is that dreaming occurs during REM sleep, and recalling your dream means your REM sleep was disrupted. Others say that remembering dreams means you did sleep well, intuiting that having dreams at all means you had a lot of REM sleep. 

Both of these may sound logical but there’s no scientific evidence either way. The problem: you may be recalling dreams because you had plenty of REM sleep, or because your REM sleep was interrupted. This presents researchers with a challenge, according to the researchers for that Sleep Health report: “Dream recall in sleep research can be conducted with dream diaries, but also by awakening participants from REM sleep when the majority of dreaming takes place.” 

Basically, there are many factors that affect your ability to recall dreams. Some of those factors are a sign of a good night’s sleep and some are not. There’s simply no data that suggests dream recall reflects the quality of sleep one way or the other. 

You don’t eat spiders while sleeping

It’s not clear where this myth came from, other than it’s popular online. The idea is that all of us eat around five spiders a year in our sleep. It’s said that the insects, seeking a warm place, climb into the mouths of sleeping people who reflexively swallow them without noticing. 

According to the Sleep Foundation there’s no documented evidence of this ever happening, let alone happening regularly. And there are all kinds of reasons to be skeptical. Most people sleep with their mouths closed, spiders tend to stay away from people, and it’s pretty hard to swallow things accidentally. Also, most people notice when a bug is climbing on them, even in their sleep. 

The good news is, it’s extremely unlikely you’ve swallowed any spiders in your sleep. This is at least one thing you can stop worrying about before bed.