By Clare Nimura
Are you tired? Whether you’re riding the subway, waiting in line at Ferris, or sitting down to do some work, lying down for a nap usually doesn’t seem like a bad alternative. Some people are supporters of the twenty-minute power nap, others try to align their nap with one sleep cycle, and yet others just pass out and wake up three hours later asking what day it is. Nap culture is rampant in our society, particularly on college campuses, where sleep often takes a backseat to work, extracurriculars, and time with friends.
The National Sleep Foundation’s 2018 “Sleep in America” poll indicates that only 10% of Americans prioritize sleep over other aspects of their lives, such as work, hobbies, and health and fitness, though the majority (65%) believe that sleep is important for productivity. According to the CDC, one in three American adults does not get enough sleep. Given these statistics, the constant wish for a nap is understandable. So how can we maximize the benefits of our naps? And how well can naps make up for a poor night of sleep?
Ideal nap conditions follow the Goldilocks principle: not too long, not too short. A nap should be longer than nodding off for a minute, but short enough that you do not experience severe sleep inertia, or grogginess upon waking. Sleep inertia occurs when you first wake up from deep sleep and levels of melatonin (a hormone that makes you tired) are still elevated. The best nap length to improve performance, alertness, and mood in healthy young adults has been suggested to be 10-15 minutes, according to studies at the Adelaide Institute for Sleep Health. This brief time ensures high performance immediately, rather than a slow fight against sleep inertia. Longer naps (~120 minutes, or one Rapid Eye Movement deep sleep cycle) contribute less to alertness but are useful for consolidating memories, especially ones tied to emotions. Different nap lengths have different benefits, so set your alarm wisely!
Other than duration, there are many factors that contribute to the perfect nap, one of which is when you sleep. For people who keep a relatively regular sleep schedule, the ideal time to nap is between 2-5pm. During this post-lunch slump, the body is using a lot of energy to digest food, and increased insulin levels can trigger the release of serotonin and melatonin, two molecules that are involved in regulating sleep. Your body’s internal clock, called the circadian rhythm, also makes it easier to fall asleep during this mid-afternoon window.
However, when you wake up from your perfectly-timed nap, are you “caught up” on sleep? Sadly, the answer is no. Napping mitigates but does not substitute for nighttime sleep. Most people don’t nap just for the fun of it, they nap to alleviate the host of problems that result from their lack of sleep. Sleep deprivation can weaken the immune system, impair memory, elevate stress levels, and increase the risk of car (or other) accidents. One of the greatest benefits of a full night of sleep is in memory, a complex process that is optimized during an extended period of sleep.
Before memories are cemented into our brain, they are consolidated. Memory consolidation is the process of stabilizing a new memory: parts of a memory are modified or deleted before the event is encoded to be stored in long term memory. On the cellular level, this process involves strengthening the connections between certain brain cells. The brain will store the most important elements of a scene or experience and discard some of the background details. This process happens most effectively during deep sleep, which is the first few hours of a full night of sleep.
A full, 7-9 hour night of sleep, always provides the most benefits in terms of memory consolidation, cognitive function, mood, and overall wakefulness, but a well-timed nap can provide a welcome boost in the middle of the afternoon. No matter the duration, naps have been proven to benefit cognitive performance, reasoning, reaction times and mood. The benefits from a nap are less variable and longer lasting than those from caffeine! However, while naps have been proven to provide benefits for memory, changing our attitude toward sleep and getting more sleep at night would be the most beneficial for our memories and most other aspects of our lives. In the meantime, though, while we make that shift toward prioritizing sleep, a nap is one of the best band aids for sleep deprivation.
Sleep, like food and water, is essential to maintain our physical and mental well-being. How has it slipped so far down our list of priorities? Over the past century, our society has grown to emphasize productivity and prosperity over leisure: Americans are working more, earning more, and spending more than in the past. This shift has been exacerbated by the rise of social media, which spreads unrealistic expectations of productivity. Hopefully, we are coming to the end of this trend. The growing body of research on the paramount importance of sleep and the escalating discussion of work-life balance are encouraging signs that we are rethinking our attitude toward sleep. So, go take a nap, but when you wake up, give some thought to how you can bump sleep higher up on your list of priorities.