How Long Should You Really Nap for Optimal Brain Function?

For some, napping feels like a luxury, but a daily afternoon nap might just be what you need to age well. A new study suggests that daytime napping might prevent your brain from shrinking as you get older.

What Is the Optimal Nap Time?

Most research shows that naps under 30 minutes offer the most benefit since it’s less likely you’ll enter the deep sleep stage or experience sleep inertia, a period of impaired alertness right after waking. 

A 10-minute nap is the most effective at improving sleep latency, fatigue, vigor, and cognitive performance, according to Yishan Xu, PhD, DBSM, a board-certified behavioral sleep medicine specialist and the host of a podcast called Deep Into Sleep.

“I often suggest patients not to take a nap longer than 40 minutes,” Xu told Verywell. 

A small study of 32 young adults found that naps lasting 10 to 60 minutes immediately improved mood and alertness. A 2021 meta-analysis also suggested that short naps can reduce fatigue, boost productivity, and improve physical performance.

Napping too much could be unhealthy. Studies have shown that excessive daytime sleepiness and napping for over 60 minutes might increase the risk of type 2 diabetes and heart problems.

Taking long naps during the day is like “eating a cake before dinner,” Xu said because it can reduce sleepiness for your actual bedtime and lead to insomnia.

What the Research Says

In the study, published in the journal Sleep Health, researchers used self-reported data from 35,080 participants aged 40 to 69 from the U.K. Biobank. Researchers examined the genetic variants associated with regular napping.

Based on the data, the researchers found a link between habitual daytime napping and larger brain volume. The difference in brain volume between people who nap regularly and those who don’t was equivalent to 2.6 to 6.5 years of aging.

However, no association was found between napping and cognitive performance, such as reaction time or visual memory.

“Our brains naturally shrink as we age, but this process is accelerated in people with neurodegenerative diseases but also cognitive decline,” said Valentina Paz, MSc, a co-author of the study and a research and teaching assistant at the University of the Republic of Uruguay.

Still, not all naps are good for you. There’s a difference between a healthy dose of daytime sleep and counterproductive excessive snoozing.

How Can You Avoid Napping for Too Long?

Xu recommends setting an alarm for a nap or asking a family member to wake you up. You can try placing your phone or alarm clock far away so that you have to move to turn it off.

To avoid feeling groggy after a nap, Xu said you should stand up right away to wake the body through movement or exposure to light. One study also suggests consuming caffeine before a nap may be the best countermeasure for sleep inertia.

Engaging in physical activities before and after naps can also help promote wakefulness. According to Xu, sometimes, people feel fatigued for a variety of reasons, such as stress and nutrition, rather than a lack of sleep. In this case, sleeping more than your body needs will only worsen your sleep quality at night.

“When my patients complain about daytime fatigue, I suggest they walk around rather than sitting or laying down, then the fatigue may pass, and they could sleep better at night,” Xu said.

Summary

Regular daytime napping might help slow down the aging process from natural brain shrinkage. Most research and experts suggest that a short nap—between 10 to 40 minutes—offers the most benefits, such as improved mood, cognitive performance, and alertness.