The Neuroscience of Napping
For Eric, a sales manager, one of the perks of working from home is being able to take a quick cat nap when even the strongest coffee can’t keep him from nodding off while reading a dull report. Unlike at the office, he doesn’t have to worry about his boss or coworkers catching him snoring at his desk — or, just as embarrassing, thinking he’s lazy. He arises from his sofa refreshed and ready to tackle the report with renewed vigor.
But for Jane, a nap makes her feel like her brain is slogging through quicksand. It also interferes with her ability to sleep at night, causing her to toss and turn, beginning the next day with a sleep deficit. So Jane has learned to avoid naps, opting for a brisk walk or an espresso when she starts to feel drowsy.
An often-cited 2009 survey indicates that, like Eric and Jane, people are divided on the issue of naps: On any given day, 34% of U.S. adults take one. Although nobody would question a toddler’s need for a midday snooze, many people, particularly in the U.S., consider adult napping to be a waste of time or downright lazy.
But the tide might be turning. Before the pandemic, several large companies, including Google, Cisco and Nike, installed spaces for employees to rest or sleep during the workday. Because sleep is one of the essential components for optimal mental health in daily life — what NLI calls “The Healthy Mind Platter” — companies are wise to consider its potential to maximize employees’ productivity, creativity, and mental well-being.
After all, research indicates that a nap can not only increase alertness, but also enhance cognitive performance, memory, and learning. The types of benefits depend on how long you sleep. Short naps (20 minutes or less) increase alertness and cognitive performance for up to 3 hours afterwards, and are less likely to cause “sleep inertia” — that confused, fuzzy-headed feeling that most people experience upon waking.
Longer naps (30 minutes or more) cause us to enter a period of deep sleep known as “slow-wave” sleep, during which brain temperature and blood flow to the brain decrease. Awaking from this deeper sleep state is jarring and requires an adjustment to higher rates of brain activity — hence, sleep inertia. However, long naps can provide greater benefits for learning and memory. When memories are first recorded in the hippocampus, they are weak and easily forgotten. Slow-wave sleep appears to push memories to the brain’s permanent storage area in the neocortex, a process called “memory consolidation.” Clearing out temporary storage areas also makes room for learning new material.
Importantly, experts say naps aren’t a substitute for a good night’s rest, which is deeper and contains more brain-restorative slow-wave sleep. So if you find that a nap interferes with your ability to fall and stay asleep at night, perhaps napping isn’t for you. However, if you’d like to give it a try or are considering a workplace napping policy, here are a few tips to help you do napping right:
Time it correctly.
The Spanish word “siesta” comes from the Latin “sexta,” or “sixth,” which refers to timing a nap for the sixth hour after dawn. Research indicates that the Spanish had it very close, with the optimal timing for a nap between 1 and 4 p.m. This timing coincides with circadian rhythms, the natural processes that regulate our sleep/wake cycle and make us most drowsy between the hours of 2 and 4 a.m., and 1 and 3 p.m. In addition, a meal (such as lunch) causes a number of physiological changes that increase sleepiness, such as blood diversion away from other organs and to the gut, and increases in sleep-inducing chemicals like tryptophan and gastrointestinal hormones. Early-afternoon siestas are also less likely to interfere with nighttime sleep than later naps.
A recent study indicated that for peak performance, athletes should allow 30 minutes post-nap to reduce sleep inertia prior to training or competition. Along the same lines, schedule your nap for at least 30 minutes before an important presentation or meeting to allow time to sweep any remaining cobwebs from your brain.
Consider the aid of caffeine.
Yes, you read that right. Most studies indicate that a 10- to 20-minute nap provides the best balance of improved brain performance and reduced grogginess upon waking, but it can be tough to not let 20 minutes turn into two hours.
Some people set an alarm to wake them up after a specified amount of time, factoring in the time it usually takes them to fall asleep, or use an app to track sleep, but you can also consider another approach called the “caffeine nap.” Here, you drink a cup of coffee immediately before your nap, and you should naturally wake after 20 minutes — about the time it takes for caffeine to make its way through your bloodstream to stimulate your brain. As counterintuitive as taking a stimulant before sleep may seem, research has shown that the combination of caffeine and a nap is better than either alone for enhancing performance and reducing drowsiness.
Realize it’s not for everyone.
If you’re a manager or leader who finds napping helpful, you can help normalize it by adding a “do-not-disturb” naptime to your daily calendar and encouraging employees to do the same. For those who don’t like to nap, they could use the time to rest, meditate, exercise, or whatever else rejuvenates them.
If you experiment with napping and still don’t enjoy it, the reason might be written in your genes. Studies suggest that individual differences in nap preferences could be due to normal variations in sleep-related genes, such as a gene called PERIOD3 that influences circadian rhythms. Napping benefits also likely vary with other factors, such as age, gender, or health status. Clearly, more research is needed, but in the meantime, how you feel and perform after a short mid-afternoon nap may be the best indication of whether you should schedule a siesta as part of your daily routine.