Studies show midday napping is beneficial
GRAND FORKS — If you enjoy an afternoon nap, go ahead, take it — and don’t feel guilty, says a Fargo physician and sleep specialist.
“Napping is very healthy,” said Dr. Samy Karaz, who practices sleep medicine at Sanford Health. “It’s actually part of the physical needs of our body.”
In our culture, it’s expected that the very young and the elderly take regular naps, Karaz said, “but all of us should be napping, really.”
Sleep plays a huge role in staying healthy, mentally and physically, he said. “It’s tied into heart and brain function.”
Napping “is good for paying off some of the ‘sleep debt’ that you acquire when you don’t get enough nighttime sleep.
“Most of us need about eight to 8 1/2 hours of sleep at night,” he said. “The vast majority of us don’t get that.”
Karaz said quality sleep is good preventive medicine that helps the body ward off ailments such as high blood pressure, heart problems, diabetes and depression.
It even affects weight gain, he said.
“We’re finding that with sleep deprivation, appetite centers (in the brain) become abnormal,” he said, “and so sleep deprivation, at least, is playing a role in obesity.”
While the research is still evolving, Karaz said, sleep deprivation also has been shown to affect the body’s immune system, which has implications for developing cancer.
Another advantage: Catching those zzz’s can make you easier to be around.
“You’ll be less irritable,” he said. Sleep deprivation has been linked to “the lowest frustration tolerance — you are more short-fused.”
If you like to nap, you’re in good company, sleep experts say.
Winston Churchill, John F. Kennedy, Ronald Reagan, Napoleon, Albert Einstein, Thomas Edison and George W. Bush are known to have valued an afternoon nap.
A short nap, about 20 to 30 minutes, has been shown to provide significant benefit for improving mood and alertness, enhancing performance and reducing mistakes and accidents, according to the National Sleep Foundation.
A study at NASA on sleepy military pilots and astronauts found that a 40-minute nap improved performance by 34 percent and alertness 100 percent.
Naps can increase alertness in the period directly following the nap and may extend alertness a few hours later in the day, the sleep foundation reported.
NASA researchers also have found that naps can improve certain memory functions and that long naps are more effective than short ones.
Longer naps can cause “sleep inertia,” which is defined as a feeling of grogginess and disorientation that can occur after awakening from a deep sleep, Karaz said.
“Some people say that when they take a nap, they wake feeling worse. That’s because they went into deep sleep — called stage 3 sleep — and have a hard time coming back to full alertness.
“But if you’re drowsy and foggy for a while (after a nap), that doesn’t mean that it wasn’t helpful,” he said. “Just don’t go back to work immediately.”
That fogginess usually lasts for only a few minutes to a half-hour but can be detrimental to those who must perform immediately after waking, according to the sleep foundation.
Post-nap impairment and disorientation are more severe, and can last longer, in people who are sleep-deprived or nap for longer periods.
“If you have the time to take a longer nap, take it — especially if you’re sleep-deprived,” Karaz said.
“If you have less time, a 20-or 30-minute nap is still helpful, especially if you’re really tired. It’s better than not napping at all.”
The vast majority of mammalian species, 85 percent, are “polyphasic sleepers,” meaning they sleep for short periods throughout the day, according to the sleep foundation.
However, humans differ from most other mammals in that they are “monophasic sleepers,” meaning that our days are split into two distinct periods, one for sleep and one for wakefulness.
It is not clear that this is the natural sleep pattern of humans, sleep experts say.
“Sleep is driven by ‘sleep pressure’ and timing, or circadian cycles, a groove in which the brain is inviting sleep,” Karaz said.
“At nighttime, there are physiological changes inviting the body to sleep.”
But humans also have a shorter circadian rhythm that invites sleep in the early afternoon, between 1 and 3 p.m., he said.
“We all should sleep two times a day,” as is the traditional practice in older cultures.
People who live in Latin American and Mediterranean countries, especially in warm climates, routinely incorporate a nap into their day-to-day lives. The blood pressure reduction that is linked to daytime sleep may be associated with the lower coronary mortality rates seen in these populations, sleep experts say.
Even in this part of the world, Karaz said, “years ago Scandinavian farmers took naps after a large midday meal. They were very hard-working people. They were in tune with their bodies.”
Napping was common “when we were not as busy and crazy” as a society, he said, “before it was obliterated by the demands of our lifestyle.”
A long nap or a nap taken too late in the day may adversely affect the length and quality of nighttime sleep, according to sleep experts. If you have trouble sleeping at night, a nap will only amplify problems.
“At some times of day, it’s harder to nap,” Karaz said. At midmorning or early evening, the brain is likely to be resistant to sleep.
“Napping in the early afternoon, in general, is ideal,” he said. “But if you are sleep-deprived, there is no time the brain wouldn’t want to sleep.”
Problems with sleep
For people who suffer from insomnia, naps would not be recommended, Karaz said. “We take advantage of ‘sleep pressure,’” to help them overcome trouble sleeping at night, he said.
“In people with untreated breathing problems, such as sleep apnea, sleep is a risk,” he said.
Driving while sleepy is extremely dangerous, according to the sleep foundation. Still, many drivers press on when they feel drowsy in spite of the risks, putting themselves and others in danger.
Sleep experts recommend that if you feel drowsy when driving, you should immediately pull over to a rest area, drink a caffeinated beverage and take a 20-minute nap.
Karaz said he expects that, at some point in the future, society will view adequate, quality sleep as just as important as exercise, good nutrition and not smoking.
He emphasized that napping “should not be viewed as a bonus — it’s a necessity.”