MADJAR

Outside, a snowstorm is gathering strength. Winds are rising to thirty miles per hour, and two feet of snow are expected over the next two days. Around the dinner table in my home, an unexpected topic of heated debate emerges once again–napping.

Danny reports that he has just enjoyed an excellent nap of an hour and a half and now feels fantastic. Ava says she doesn’t get it. Whenever she takes a nap, she wakes up even more tired. Danny adds that she sometimes wakes from a nap a little grumpy. Sharon says she takes only short naps, and only occasionally–when the dew point is right, the weather agreeable, and the stars perfectly aligned.

I tell them that napping doubles your life. My grandmother said so.

“Doubles your life?” Danny asks. “I read somewhere that the opposite is true. I was actually worried about you, because you always take naps on the weekends. I hope napping isn’t a prescription for early death.”

“Napping doubles your life because you wake up twice a day–to a newly formed existence. That’s what my grandmother Amalia used to say. She wasn’t a scientist, but she had common sense.”

Ava smiles. “Napping would make a great subject for one of your articles.”

She is right. It is time to explore the question: What are we talking about when we’re talking about midday napping?

Danny’s concern, it turns out, is not entirely unfounded. In a 2024 meta-analysis titled “To nap or not? Evidence from a meta-analysis of cohort studies on habitual napping and health outcomes,” researchers synthesized data from dozens of large population studies. Including hundreds of thousands of participants, the report suggested that habitual daytime napping was associated with higher risks of several adverse outcomes, including cardiovascular disease and overall mortality.

Importantly, the association appeared particularly strong for “long naps”–those lasting an hour or more. At first glance, this seems to support Danny’s fear that a pleasant afternoon rest may be quietly shortening one’s life. But science, like life, is rarely that simple.

The authors of the study were careful in interpreting their findings. Because the analysis relied on observational cohort studies, it could identify associations but not direct causation. Frequent napping may not be causing illness; it may instead be a marker of underlying health problems. People who nap regularly are more likely to have poor nighttime sleep, sleep apnea, chronic disease, or the fatigue that accompanies aging. In such cases, the nap is less the culprit than the messenger.

Yet another major study seems to tell a different story, one that offers hope to the occasional napper. In 2019, researchers from Switzerland published a study in the journal Heart titled “Association of napping with incident cardiovascular events in a prospective cohort study.” The investigators followed 3,462 adults for five years, examining how often they napped and whether they later experienced heart attacks or strokes.

Surprisingly, the researchers found that people who napped once or twice per week had a lower risk of cardiovascular events than people who did not nap at all. More frequent napping, however, showed no protective association. The duration of the naps was not significantly related to risk in this specific group, suggesting that frequency might be the more critical variable.

The contradiction between these two studies dissolves once one looks more closely at what each was measuring. The 2024 meta-analysis focused on habitual, daily napping, which often reflects chronic fatigue or disrupted sleep. In contrast, the Swiss study highlighted the benefits of the occasional, perhaps more restorative nap. Seen this way, the studies are describing two different biological phenomena: the “compensatory” nap taken by the ill, and the “restorative” nap taken by the healthy.

What explains Ava’s complaint of waking up feeling worse? Researchers call this Sleep Inertia, a state of grogginess and impaired alertness. The subject was reviewed by Lynn Trotti in 2017 in Nature and Science of Sleep. During sleep inertia, reaction times slow and attention falters because the brain has been pulled out of a deep sleep stage.

Our brains cycle through different stages, moving from light sleep into deep “slow-wave” sleep. If a person wakes during these deeper stages–which is much more likely after thirty minutes–the brain may take up to an hour to fully “reboot.” Experimental studies published in the journal Sleep in 2023 confirm that very short naps (around ten minutes) produce minimal inertia, whereas thirty-to-sixty-minute naps often produce significant grogginess, even if cognitive performance improves later in the evening.

This helps explain the disagreement around our dinner table. Danny likely completed a full sleep cycle. Ava emerged from the depths of slow-wave sleep with her brain still half-submerged. And Sharon, with her cautious “astrologically timed” short naps, has essentially mastered the “power nap” strategy that sleep scientists now recommend.

Somewhere in the background, my grandmother Amalia’s wisdom still echoes. When you nap, you wake up twice a day into a newly formed existence. Whether science will ultimately agree with her remains an open question.