Editor’s note: Researchers exploring Mars via rover and satellite have to adapt to the longer day on the Red Planet. Katie Worth, whose Can Earthlings Adapt to the Longer Day on Mars? for Scientific Americanearlier this week describes the consequences of sleep-pattern changes, is trying it out herself. Follow her experiences in living on “Mars time” at this blog to see how it affects her sleep and behavior. This post is the sixth in a series.
I began this experiment two and a half weeks ago with a bedtime of 2 A.M. Today, it’s 2 P.M. If I had trotted half way around the globe as I have trotted around the clock, matching my ever-evolving Martian schedule to the Earth’s time zones, I would now be in Tokyo.
And Tokyo would be an ideal location for me, because lately I’ve been indulging in a lot of inemuri—the Japanese practice of “sleeping while present,” aka “napping on the job.” That favorite pastime of Homer Simpson is socially acceptable in Japan, where it’s seen as a sign of commitment to work (see former Japanese Prime Minister Junichiro Koizumi display impressive commitment to his work here.)
In fact, the Japanese are among the world’s leading nap innovators: A few months ago, the nation that introduced us to capsule hotels and napping salons opened its first “cuddle caf,” where you can pay to take a nap while platonically cuddling a stranger. Seriously.
Of course, Japan’s not the only place you can catch some zzz’s without fear of stigma. Nap advocates abound worldwide, and they are easily spotted, because when they’re not sleeping they are usually enthusiastically expounding upon the delights of a doze. If you’re confused about exactly how to nap, this book promises to give you all the information you need, knowledge they assert will make you happier, smarter and skinnier, and also might save your life. If you would love to nap but simply don’t have the technology to do so, the Power Nap Capsule can provide you that for a mere $25,000.
Once you have all the basics down, be sure to celebrate National Workplace Napping Day on March 14. It’s no coincidence the celebration of snooze falls right after we’re hit with Daylight Saving Time, that merciless scourge that tragically deprives hundreds of millions of Americans of a whole hour of sleep every single year. (Attention celebrities in search of causes: This menace can and must be stopped!)
But before you abandon this blog post and surrender to the bountiful benefits of a siesta, I should tell you that sleep scientists are hardly unified in their stance on napping. For babies and children, napping is an unequivocally good idea, at least for the sanity of their parents. But for adults, it’s not always obvious whether daytime naps help or harm the quest for the perfectly rested body and soul.
I called Michael Perlis, director of the University of Pennsylvania’s Behavioral Sleep Medicine Program, for a better understanding of why the question “Should I take a nap?” can’t always be answered with a simple yes or no.
The risk that lurks within every catnap is that it can keep us from sleeping later on, Perlis says. For most of us, it takes the better part of a day to accumulate the level of sleepiness we need to doze off at night. So if we throw in a nap, especially late in the day, we may wake up feeling refreshed, but we’ll be counting many more sheep than we’d like later that night.
But that’s only a generality. How we each specifically respond to naps depends on three things, says Perlis:
- Our sleep need—the amount necessary to be fully rested. The average is 7 or 8 hours, but it can vary by an hour or two either direction from person to person. Unfortunately, there isn’t yet a good way to directly measure our need, though tracking our sleep patterns in reference to how we feel the next day can give us a pretty good approximation.
- Our sleep ability—how good we are at sleeping. This factor is more fickle, and is vulnerable to influences like whether we are uncomfortably warm or cold, uncomfortably pregnant, overly caffeinated, suffer from a sleep disorder, or are feeling tormented by the appalling life choices of a loved one.
- Our sleep opportunity—the amount of time we are in bed, attempting to sleep. This is the dynamic most within our control, though many of us frequently sacrifice it, say if we’re working 70 hours a week, have the propensity to stay out all night drinking, or have the hots for tonight’s guest on Late Night with Jimmy Fallon.
Depending on how those three forces play out for us as individuals, naps can be OK—but they usually aren’t, says Perlis. He says we simply need to experiment to find out.
“If you sleep 4 to 6 hours at night and 2 during the day, and you feel productive and happy and healthy and handsome, then it works out well for you,” Perlis said. “Most adults can’t do that.”
He warned there’s also a danger in getting too much sleep, which can happen if our ability to sleep outdoes our need.
“That mismatch that may make you sluggish and stupid and unappealing and fat,” he said.
As for me, I come from a long line of proud nappers. My dad is famous in my family for his borderline narcolepsy, and can often be spotted nodding off mid-conversation, particularly when he finds the conversation dull. His must be recessive genes, though, because I rarely manage to take naps. When I do, I often wake up crabby as hell, and groggy rather than refreshed.
Nonetheless, as my sleep deprivation has accumulated over the last 18 days, I’ve been taking short naps almost daily. This new habit took a strange turn over the last three days, each time around 2 A.M. (about noon on my Martian schedule), when I found myself suddenly overcome with a sweaty fever and fatigue, like the feeling that smacks you when you first get the flu. Each time, I plummeted into a deep abyss of sleep, and woke up 30 minutes later feeling exhausted but OK, no longer preoccupied with revenge fantasies aimed at my editors, who got me into this mess to begin with.
Perlis noted that we don’t know much about how our ancestors slept, before the ubiquity of electric lights and addictive cell phone games. Medical anthropology suggests that many cultures may have been polyphasic sleepers, snoozing in multiple chunks. People living in those cultures hit the hay at dusk, slept for four hours, woke up for a couple of hours to think, or appease their horniness, or make sure everyone was safe, then retired again for the rest of the night.
If humans ever colonize Mars, they’ll have the opportunity to create a new culture there, and with it, new rituals about sleeping. Maybe those distant immigrants will spend their surplus 40 minutes a day napping. Maybe they’ll use it to break up their 8 hours of sleep with procreation, like our ancestors. Or maybe the Japanese will show up with a cuddle caf, and the colonists will snooze away their extra time in the arms of Martian strangers.
Previously in this series: