The Best Investment You Can Make This Afternoon
In ancient Rome, the clock looked a lot different... and so did the workday.
The Ancient Romans divvied up the day based on 12 hours of sunlight. So their "6 o'clock" fell right around midday, or noon. They called it the hora sexta, which translates to "sixth hour."
When the hora sexta hit – and the sun was at its most punishing – agricultural workers would drop their tools to rest.
Over time, that midday pause became a bit of a tradition of sorts, so much so that the hora sexta ended up evolving into a word you're probably familiar with: siesta.
As it turns out, this agricultural survival tactic wasn't just about avoiding the hottest part of the day... It also happened to sync up surprisingly well with human biology.
Today, of course, most Americans follow a 9-to-5 work schedule. And when that inevitable 3 p.m. fatigue hits and your eyelids feel like lead, you might probably give in to an extra cup of coffee and try to soldier through with a sluggish brain.
But science shows that fighting your body's natural rhythms isn't always the best move...
The Biology of the Siesta
That afternoon drag isn't a sign of laziness or lack of focus... It's a predictable biological pattern.
Part of it is tied to your circadian rhythm, which creates a natural dip in alertness in the early afternoon, even if you're well rested.
Lunchtime can amplify that feeling... After that meal, your pancreas secretes insulin to help move glucose from the food you've eaten from your bloodstream and into your cells for energy.
This necessary release of insulin also happens to allow more tryptophan, a naturally occurring amino acid, to enter your brain. And tryptophan is also a building block for the "feel good" neurotransmitter serotonin and the "sleep" hormone melatonin, which are key for relaxation and sleep regulation.
The result? You feel calmer... and a bit sleepier. So if you lean into that with a short nap, that unlocks some real benefits.
Short naps – especially those less than 30 minutes long – have been shown to improve alertness, reaction time, and memory.
When we nap, the right side of our brain remains active while the left side sleeps. It is thought that the right side of the brain uses this time to do some housekeeping... It clears your temporary memory storage by pushing information into your long-term memory.
Cognitive benefits aside, there's immunological ones, too... Napping helps to regulate your body's response to inflammation through the release of cytokines. These chemical-messenger proteins enable cell communication, which is crucial for repairing areas of the body experiencing inflammation, infection, or trauma.
Don't Be Scared to Nap
Now, you might have seen a flurry of recent headlines warning that excessive napping increases mortality risk – specifically in older adults. But don't jump to the worst conclusion and think, "Napping is dangerous – avoid at all costs"...
These articles stem from a study recently published in JAMA Network Open. Researchers tracked 1,338 older adults over a 19-year period and found that increases in daytime sleep duration and frequency were associated with higher mortality risk.
But since this was an observational study, it shows a correlation and not a causation. These longer or more frequent naps didn't necessarily cause worse outcomes. Instead, they may be a marker of underlying health problems.
Older adults who start sleeping more during the day could be experiencing early stages of conditions like cardiovascular disease, sleep disorders, depression, or neurodegeneration – all of which can increase fatigue.
So just keep in mind that if you happen to find yourself regularly needing hour-long naps... dozing off unintentionally... or still feeling exhausted afterward, it's a good idea to bring it up to your doctor.
On the flip side, if you're intentionally taking a strategic, 20-minute siesta to recharge and beat the dreaded afternoon slump, that's an entirely different story...
A 2023 study from the University College London used genetic data to look at habitual napping and found a link between a genetic tendency to nap and having slightly larger brain volume. That's great news for aging brains. (As we age, our brains naturally shrink which can lead to cognitive decline.)
And then there's a 2021 study from China involving 2,214 people aged 60 and older. Participants were split into two groups: the regular nappers and the non-nappers.
After multiple cognitive tests, the regular nappers significantly outperformed the non-nappers in spatial orientation, language fluency, and short-term memory.
How to Nap Like a Pro
Did you know that there are different types of naps?
Scientists classify naps into different categories based on your bodily needs. For instance, a "recovery nap" helps compensate for lost sleep, while a "prophylactic nap" prepares you for future sleep loss. And an "essential nap" happens when you're sick and need to support your immune system.
But for daily cognitive enhancement, you want what's called an "appetitive nap"...
This is the nap taken for the pure enjoyment and mental clarity provided.
Here's how to get the cognitive boost without the grogginess...
- Set a strict alarm. Aim for 10 to 20 minutes – that's the absolute sweet spot. Any longer and your body will enter into deep sleep, leaving you feeling sluggish when you finally wake up. Do what I do and set your timer for 20 minutes, tops.
- Time it right. Aim for the midway point of your day, usually between 2 p.m. and 3 p.m. Napping too late will disrupt your nighttime sleep rhythm.
- Create a sleep-friendly sanctuary. Nap in a spot that's cool, quiet, dark, and comfortable.
Finally, I do my best to set aside stressful thoughts that can keep me awake. Deep belly breathing until the z's kick in helps. And I recommend reminding yourself that you deserve this brief respite and it's a vital investment in your afternoon productivity and overall health.
What We're Reading...
- Something different: A nasal spray that reverses brain aging?
Here's to our health, wealth, and a great retirement,
Dr. David Eifrig and the Health & Wealth Bulletin Research Team
April 23, 2026