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8 Scientific Benefits of Napping

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Even on the best of days, life can be exhausting. If you find your energy flagging in the middle of the day, you might like to know that 34 percent of Americans nap. Napping is a healthy way to restore the deficits of sleep deprivation. Whether you bow down to the ritual of a mid-afternoon siesta or never stop to snooze, you may think twice about the power of napping after reading about these eight benefits.

1. NAPPING CAN BOOST YOUR IMMUNE SYSTEM.

Sleep deprivation—particularly repeated, chronic lack of sleep—takes a toll on your neuroendocrine and immune functions by increasing inflammatory molecules known as cytokines, as well as stress hormones like cortisol and norepinephrine. A 2015 study in the Journal of Clinical Endocrinology & Metabolism took 11 healthy young men and restricted them to a night of only two hours of sleep. Blood and urine tests measured higher cytokines and levels of norepinephrine in both groups after sleep deprivation. The following day, one group was given two half-hour naps, while the control group did not have any naps. Blood and urine samples of those who napped showed that their cytokines and norepinephrine levels had returned to normal, as though they had never lost a night of sleep.

2. A NAP CAN IMPROVE NIGHT ALERTNESS.

For people who work at night, or through the night, several studies have shown that naps from between 30 minutes and four hours long that are taken in advance of the shift—what's known as a "prophylactic nap"—improve performance and alertness. These naps can also improve nighttime driving alertness on the way home from the shift. However, most of these studies also include the administration of caffeine, which likely contributed. Yet a 1995 study in Sleep, which compared naps and caffeine, found that "naps, in general, provided longer and less graded changes in performance, mood and alertness than did caffeine, which displayed peak effectiveness and loss of effect within about six hours."

3. NAPS + CAFFEINE ARE A ONE-TWO PUNCH AGAINST SLEEPINESS. ASK SURGEONS.

Surgeons must often perform continuous surgery for hours longer than the average person would ever have to persist at a task. A 1994 study in the journal Ergonomics found that naps were indeed effective at keeping surgeons who had to remain awake for 24 hours alert, but only when caffeine was administered, too. Neither naps or caffeine alone were sufficient.

4. TO IMPROVE DAYTIME ALERTNESS, TAKE FREQUENT NAPS.

Daytime napping also appears to improve mental alertness and performance, according to a number of laboratory studies. However, researchers found that shorter naps were more effective than longer ones. The most effective time of them all was 10 minutes, which produced the best outcomes in all sleep measures including "subjective sleepiness, fatigue, vigor, and cognitive performance." A 30-minute nap could produce the same effects but brought about "a period of impaired alertness."

5. NAPS HELP YOU LEARN NEW SKILLS.

If you want to get better at learning a new skill, you might want to take more frequent naps. A 2006 study in Biological Physiology broke participants into two groups: those who napped frequently and those who napped sporadically. Each group was given a nap before a reading task. Habitual nappers—people who reported napping frequently—did better on the reading and retention task. Researchers determined that the brains of habitual nappers consolidated motor learning better, which is part of the process of learning a new skill.

6. IMPROVE YOUR PHYSICAL STAMINA WITH NAPPING.

It turns out that napping is not only just good for mental processes, but has a positive impact on physical stamina and performance as well. A 2007 study in the Journal of Sports Sciences put 10 healthy men through a series of sprints before and after a 30-minute, post-lunch nap. Sprint times improved after the naps, suggesting to the researchers that a post-lunch nap "improves alertness and aspects of mental and physical performance following partial sleep loss." They suggest that napping may be an important part of the regimens of athletes who are undergoing restricted sleep during training or competition.

7. NAP TO IMPROVE YOUR MEMORY.

One of the many functions of regular nighttime sleep is to consolidate memory. A 2010 study in Neurobiology of Learning and Memory set out to see whether daytime naps also improve memory processes, particularly associative memory (the ability to make connections between unrelated objects). Thirty-one healthy participants were given a learning task at 12 p.m. to memorize two sets of face-object photograph pairs. The objects in each pair occurred in both sets but were paired with different faces. Participants were broken into two groups: those who had a 90-minute daytime nap or those who did not. At 4:30 p.m., participants who napped showed notably better retention of associative memory.

8. A 90-MINUTE NAP IS AS GOOD AS A FULL NIGHT’S SLEEP FOR PERCEPTUAL LEARNING.

Previous research demonstrated that people perform better on a visual texture-distinguishing task after a night of sleep than they do immediately after learning it. A 2003 study in Nature Neuroscience found that people performed just as well on the test after a 60- to 90-minute nap as they did after a full night of slumber.

"What's amazing is that in a 90-minute nap, you can get the same [learning] benefits as an eight-hour sleep period," lead author Sarah Mednick said in an interview with the American Psychological Association. "The nap is having an additive benefit on top of a good night of sleep."

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Feeling Down? Lifting Weights Can Lift Your Mood, Too
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There’s plenty of research that suggests that exercise can be an effective treatment for depression. In some cases of depression, in fact—particularly less-severe ones—scientists have found that exercise can be as effective as antidepressants, which don’t work for everyone and can come with some annoying side effects. Previous studies have largely concentrated on aerobic exercise, like running, but new research shows that weight lifting can be a useful depression treatment, too.

The study in JAMA Psychiatry, led by sports scientists at the University of Limerick in Ireland, examined the results of 33 previous clinical trials that analyzed a total of 1877 participants. It found that resistance training—lifting weights, using resistance bands, doing push ups, and any other exercises targeted at strengthening muscles rather than increasing heart rate—significantly reduced symptoms of depression.

This held true regardless of how healthy people were overall, how much of the exercises they were assigned to do, or how much stronger they got as a result. While the effect wasn’t as strong in blinded trials—where the assessors don’t know who is in the control group and who isn’t, as is the case in higher-quality studies—it was still notable. According to first author Brett Gordon, these trials showed a medium effect, while others showed a large effect, but both were statistically significant.

The studies in the paper all looked at the effects of these training regimes on people with mild to moderate depression, and the results might not translate to people with severe depression. Unfortunately, many of the studies analyzed didn’t include information on whether or not the patients were taking antidepressants, so the researchers weren’t able to determine what role medications might play in this. However, Gordon tells Mental Floss in an email that “the available evidence supports that [resistance training] may be an effective alternative and/or adjuvant therapy for depressive symptoms that could be prescribed on its own and/or in conjunction with other depression treatments,” like therapy or medication.

There haven’t been a lot of studies yet comparing whether aerobic exercise or resistance training might be better at alleviating depressive symptoms, and future research might tackle that question. Even if one does turn out to be better than the other, though, it seems that just getting to the gym can make a big difference.

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The Best Way to Wipe Your Butt, According to the Experts
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Curtis Asbury, MD sees it all the time. A patient comes in with blotchy, red, irritated rectum and insists they’re not doing anything unusual. Peering into their sore bottom, Asbury nods solemnly, then delivers news most people never expect to hear.

“You’re not wiping correctly,” he says.

A dermatologist practicing in Selbyville, Delaware, Asbury has seen an uptick in the number of people coming in expressing dissatisfaction with their rectal hygiene. Whether it’s due to misguided parental instruction during toilet training or wiping on sheer instinct, some of us are simply not maintaining one of the most potentially dirty crevices of our body. And the consequences can be irritating.

“It’s called perianal dermatitis,” Asbury tells Mental Floss, describing the kind of topical irritation that afflicts people who are wiping poorly, infrequently, or overzealously. In an attempt to clean their rear end, some people scrub so violently that the American Society of Colon and Rectal Surgeons has given a name to the resulting tenderness: Polished Anus Syndrome, or PAS.

Fortunately, the key to avoiding PAS and other rectal misadventures is relatively easy. Here are some pro tips for a clean butt.

GIVE UP WET WIPES

For starters, Asbury recommends that people stop using the pre-moistened cloths, which are heavily marketed to promote a sparkling cavity. Use of the wipes has been associated with allergic reactions to methylisothiazolinone, a preservative used to inhibit bacterial growth while products are on store shelves. “Even the all-natural ones can cause problems,” he says, since any kind of chemical present in the wipes isn’t usually rinsed off right away.

Does that mean you should reach for dry toilet paper instead? Not quite. “It’s healthier, certainly, to clean your body with water," Asbury says. "Nobody takes a dry piece of paper, rubs it over their skin, and thinks they’re clean.” Even the Greco-Romans (332 BCE–395 CE) knew this, as one historical account from the philosopher Seneca revealed that they used a damp sponge affixed to a stick as a post-toiletry practice. Of course, some ancient cultures also wiped with pebbles and clam shells, among other poor ideas, so perhaps we should stick with contemporary advice.

INVEST IN A BIDET

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Asbury is an advocate of the standalone or add-on toilet accessory that squirts a spray of water between your cheeks to flush out residual fecal matter. While bidets are common in Europe and Japan, the West has been slower to adopt this superior method of post-poop clean-up; others might be wary of tapping into existing home plumbing to supply fresh water, even though DIY installation is quite easy. For those patients, Asbury has developed an alternative method.

TRY PAPER TOWELS AND WATER

“What I tell people to use is Viva, a really soft, thick paper towel made by Kleenex,” he says. “You get a squirt bottle and you leave it near the toilet and moisten the paper towel.” Regular toilet paper is usually too flimsy to stand up to a soaking, while normal paper towels are too harsh for rectal purposes. Viva is apparently just right. (And no, Asbury is not a brand ambassador, nor does Kleenex endorse this alternative use.)

This advice does come with a major caveat: Viva wipes are not flushable and might very well clog your pipes if you try to send them down the drain. When Asbury recommends the technique, he advises people to throw used towels in the trash. If you find that idea appalling, and provided your butt is not already red from bad wiping strategy, lightly moistening a wad of durable toilet paper should do the job.

DRY THOROUGHLY BUT GENTLY

Once you’ve wiped enough to see clean paper, take a dry square and mop up any excess moisture. Whether it’s wet wipes or bidets, some people don’t bother with this step, but “it would be weird not to dry,” Asbury says. Occasionally, moisture can lead to intertrigo, which is irritation in skin folds, or a fungal infection.

You also want to have a soft touch. “I see people scrubbing hard,” Asbury says. “That just makes the problem worse.” Excessive wiping can lead to micro-tears in the anal tissue, causing bleeding and discomfort.

WIPE IN THE RIGHT DIRECTION

Make sure to go from front to back, pushing waste away from the groin. This has traditionally been advised for women to keep poop away from the vaginal canal and prevent urinary tract infections. While Asbury hasn't found specific studies to back up this advice, he still believes it's likely more hygienic. There’s also something to be said for sitting while wiping, since ergonomically, it may keep your perianal area open. But if you’re uncomfortable reaching into the toilet to wipe, standing should suffice.

Assuming you’ve done all that and you’re still feeling discomfort, Asbury warns it might be something else. “If you’re not feeling clean, there could be issues with your sphincter,” he says. Weakened muscles can cause leakage. But generally, it’s dry-wipers who have trouble getting everything they need to get. For the hard-to-clean, Asbury advises that they make the switch to a bidet.

“It’s cold at first,” he says. “But you get used to it.”

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