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."

6 Dreaded Tasks That Are Actually Great For Managing Stress

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High levels of the stress hormone cortisol can wreak havoc on your body. (According to a recent study on middle-aged adults, stress not only impairs memory but may even cause the brain to shrink!) Thankfully, some commonly dreaded activities can help reduce your frazzled state.

1. Washing the Dishes

According to a 2014 study published in the journal Mindfulness, a “mindful” approach to dishwashing could reduce stress. “A sample of 51 college students engaged in either a mindful or control dishwashing practice before completing measures of mindfulness, affect, and experience recall,” the study states. “Mindful dishwashers evidenced … increases in elements of positive affect (i.e., inspiration) [and] decreases in elements of negative affect (i.e., nervousness)." In other words, with the right mindset, zoning out in front of a sudsy sink is basically Nirvana.

2. Decluttering Your Home

Research suggests that clutter is more likely to stress out women. In 2010, a study in the Journal of Personality and Social Psychology looked to see how married couples dealt with (and felt about) messy homes [PDF]. “The wives in the study who perceived themselves as having a cluttered home or a home that needed work tended to have increased levels of cortisol throughout the day,” Emilie Le Beau Lucchesi wrote in The New York Times. "Those who weren’t feeling cluttered, which included most of the men in the study, had cortisol levels that tended to drop during the days.” So tidy up!

3. Exercising In A Group

Working out can feel like a chore, and exercising with a group can be a tad embarrassing—especially if you’re not on the same fitness level as everybody else. But according to research in the Journal of the American Osteopathic Association, exercising with a group is more beneficial at reducing stress than working out alone. “Researchers found that working out in a group lowers stress by 26 percent,” according to the press release. Go ahead and book that spin class!

4. Sniffing Your Partner’s Laundry

No sane person puts “sniff your significant other's dirty socks” on their to-do list, but perhaps they should. A 2018 study published in the Journal of Personality and Social Psychology shows that sniffing a loved one’s clothes can reduce stress. In the study, 96 women sniffed one of three scents—a neutral smell, their romantic partner’s scent, or the scent of a stranger. The stranger’s smell caused cortisol to spike. But their partner’s smell? It reduced stress.

5. Dwelling On Your Failures

The title of this study, which appeared in the journal Frontiers in 2018, says it all: “Writing About Past Failures Attenuates Cortisol Responses and Sustained Attention Deficits Following Psychosocial Stress.” According to the study, “[W]riting about a previous failure may allow an individual to experience a new stressor as less stressful, reducing its physiological and behavioral effects.” It sounds paradoxical, but the next time you're facing a crazy situation, just reflect on a time when it all went wrong—and things might not feel so bad.

6. Singing For All to Hear

For the shy and tone-deaf, singing in a group might be a anxiety-fueled nightmare—but they should try it anyway. A pilot study presented at the Society for Neuroscience conference last year showed that, in people with Parkinson's disease, singing in a group can reduce heart rate, blood pressure, and cortisol levels. (Researchers cautioned that this is preliminary data.) The findings jibe with a 2016 study from Drexel University that found, no matter your skill level, making art usually reduces cortisol levels [PDF].

Nearly Half of American Adults Don't Know Their Own Blood Type

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iStock.com/nzphotonz

If you know your blood type, you’re better off than nearly half of Americans. Of the 1004 adults in the U.S. who answered a recent Quest Diagnostics survey, only 57 percent said they knew whether they have type A, B, AB, or O blood.

This is roughly the same number of people who could recall their childhood phone number (55 percent), the survey revealed. By comparison, 74 percent of respondents remembered their lengthy Wi-Fi password, and 75 percent knew how much money was in their bank account.

For many, other personal health information was even murkier. Fewer than two in five people knew their cholesterol or blood sugar levels. Considering that these details provide important insights into one’s risk for certain diseases, survey administrators said this is a cause for concern.

“With consumers increasingly engaged in their own and their loved ones’ health care, it’s critical that they ‘know their numbers’—and have those numbers readily accessible—to ensure productive communication with their healthcare provider for both routine and critical care,” Cathy Doherty of Quest Diagnostics said in a press release.

With the exception of emergencies, at which time you may receive a universal donor's O-negative blood, doctors will almost always conduct blood typing and cross-matching tests to determine your blood type and identify minor antigens in your blood before conducting a transfusion or surgery.

It’s still important to know your blood type for other reasons. Newborn babies, for example, can develop hemolytic disease if their Rh blood type (meaning whether it's positive or negative) doesn’t match their mother's. And depending on your blood type, you may also have an increased risk for blood clots, heart disease, certain types of cancer, and even severe diarrhea and mosquito bites.

If you know your blood type, you’re also in a better position to donate blood and help people in need if there’s a natural disease or emergency, or if blood banks simply have a low supply. O blood tends to be the highest in demand (and O-positive is the most common blood type), but blood banks may issue public notices from time to time if they need a particular type.

If you’re unsure of your blood type, clinical labs like Quest Diagnostics offer blood type tests. You can also order test kits online from Amazon.

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