National Napping Day: Why Having a Brief Sleep Isn't That Good For You, According to Recent Research

Today is National Napping Day (March 9, 2020)—a day that instantly makes us all want to take an afternoon siesta.

Organizations such as Google and the Huffington Post consider napping to be an important part of the working day. Both companies have the EnergyPod, a chair designed for napping in the workplace.

But is napping—whether at work or at home—really that good for your health? Newsweek checks out the latest research from across the world to put this question to bed.

National Napping Day 2020 iStock
Stock image: Research from 2020 shows that napping might not be all it's cracked up to be. iStock

Is napping good for your health?

Daily naps could potentially lead to a stroke

Research conducted by the Department of Critical Care Medicine, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China, found a link between those who had frequent, long naps and a higher risk of having a stroke. An article discussing the study is pending publication in the European Journal of Neurology.

The study was based on the Sleep Heart Health Study—which is funded by the National Heart, Lung, and Blood Institute—and assessed napping habits of 4,757 participants. The researchers then followed up with people with different habits, sleep durations and frequencies, up until the first stroke occurred or by the final censoring date.

The results showed that compared with those who didn't take naps, people taking naps with a duration of over 60 minutes had a higher risk of stroke. There was also an increased risk of stroke among participants who took daily naps. It's also worth noting that the average age of the participants was 63, so what impact it would have on younger people is not known.

Long naps could reduce muscle damage for athletes

According to research due to be published in the International Journal of Sports Physiology and Performance, nine male judokas performed four test sessions which showed that napping helped performance. Test sessions included the running-based anaerobic sprint test, reaction time, Hooper index, and Epworth Sleepiness Scale. Muscle-damage and antioxidant status were evaluated before and after the exercise.

The results showed that napping could be preventive against performance degradation caused by sleep loss, with short napping being more beneficial for frequent decision making. Interestingly, a long nap was shown to prevent muscle and oxidative damage, even for higher performances.

Taking naps could contribute to a lower sperm count

Research published this year in journal Environment International showed that there's a link between shorter periods of sleeping and lower sperm count and motility.

The study investigated whether sleep was a contributing factor towards the quality of semen, screening 842 men who were looking to be potential sperm donors. The participants were assessed on their night sleep and daytime napping, as well as their sleep quality. The results showed that compared to men who got a total of 8 to 8.5 hours a day, men who slept less than 6 hours or more than 9 hours had lower sperm volume of 12 percent.

Napping might cause hypertension in women

Researchers from China and the U.S. conducted a study that looked at whether having an afternoon nap was linked to hypertension. Published in the journal Heart Lung in early 2020, the research included nearly 8,000 Chinese participants and found that middle-aged and older women who napped for over 90 minutes were 39 percent and 54 percent respectively more likely to have hypertension.

The links were not as significant in middle-aged and older men.

Napping can help with long-term memory retention

A study published in the jorunal Sleep in 2019 looked at whether young adults could improve their memory by taking naps when studying, rather than "cramming."

Three separate groups—napping, taking a break and cramming—studied information over a period of five and a half hours. The napping group took a nap for one hour, and another group took a break. One group didn't stop learning. The students were then asked to recall what they had learned 30 minutes later and then again after one week.

Students took part in research over the course of five and a half hours. Sleep Research Society

When tested 30 minutes after learning, cramming and napping led to significantly better memory recall. However, after a week, napping maintained the advantage, but cramming did not.

Students who napped were able to retain information for longer than those who crammed. Sleep Research Society