In the quiet hours before dawn in Oman, many people rise not for an alarm clock, but for the call to prayer. They pray, then often drift back to sleep or later settle into an afternoon nap to make up the rest. Sleep researcher Mohammed Al-Abri from Sultan Qaboos University in Muscat notes that this pattern is simply part of everyday life there. But this kind of segmented sleep is far from unique to Muslim-majority countries. Teenagers with shifting body clocks, new parents whose nights are broken by feedings, women navigating perimenopause and menopause, and older adults who no longer sleep as deeply as they once did all often struggle to get the recommended seven to nine hours in one uninterrupted stretch. Night owls forced into early school and work schedules are chronically shortchanged, while shift workers try to squeeze rest into odd hours that fight their natural biology. And in many of the hottest parts of the world, people have long used a midday siesta to escape the brutal sun. In other words, napping and splitting sleep across the day are normal, widespread human behaviors. Yet for decades, sleep science has been oddly obsessed with the idea that healthy sleep means one solid block at night. Researchers writing in Brain Medicine argue that this narrow focus misses something crucial: how people sleep matters just as much as how much they sleep. If we are serious about helping people feel rested, science needs to pay far more attention to patterns that combine a core nighttime sleep with naps spread across the twenty-four-hour day.
But before we can do that, we need to stop treating naps as a simple yes-or-no behavior. That is one of the central arguments made by researchers in a recent Sleep Health review. Naps are not all the same. A quick ten-minute power nap is a completely different experience from a two-hour deep slumber. A nap taken at noon is not the same as one taken at five in the evening. A daily siesta in a culture that closes shop after lunch carries a different meaning and rhythm than a stolen nap in a car between shifts. And someone who naps because they are genuinely sleep-deprived is in a different situation from someone who naps because they simply enjoy it. Yet much of the existing research lumps all naps together, and that has led to wildly contradictory conclusions. Some studies suggest napping harms health; others suggest it helps. Lost in all this noise is practical guidance for the millions of people who are simply exhausted. Line Victoria Moen, an occupational health researcher in Norway who was not involved in the studies, puts it bluntly: the evidence is too fragmented. We cannot confidently tell people whether splitting their sleep is a smart strategy or a risky one. What we can say is that the current one-size-fits-all approach is failing. The conversation needs to shift from “naps are good or bad” to a deeper understanding of what kinds of naps work for whom, and under what circumstances.
This is not a brand-new question. Historians have uncovered fascinating evidence that segmented sleep used to be the norm in many places. In his book At Day’s Close, historian A. Roger Ekirch describes how medieval Europeans often slept in two distinct blocks. They would go to bed around sundown, wake in the middle of the night for an hour or two, and use that time to pray, meditate, do light chores, or even have sex. Then they would settle back into a second sleep until sunrise. That pattern made sense in a world without electric lights, where darkness naturally stretched the night. But our modern world is bathed in artificial light and glowing screens, and the idea of waking in the middle of the night now feels like a problem rather than a natural rhythm. Still, the modern approach is not working. Across industrialized countries, people are chronically sleep-deprived, and the consequences are serious: memory lapses, weakened alertness, poor performance at work and school, heart disease, obesity, and a host of other physical and mental health struggles. The standard advice to practice better sleep hygiene—dimming lights, putting away screens before bed, keeping a consistent schedule—is well-meaning but often impractical. What about the roughly one-fifth of workers in industrialized countries who do shift work? They are expected to perform with a body that is out of sync with the sun, and a single daytime sleep block is usually lighter, more fragmented, and less restorative than nighttime sleep. Researchers have begun to wonder whether these individuals might be better off splitting their sleep into chunks before and after shifts. But the science does not yet offer clear answers. We are still trying to figure out whether a two-sleep pattern can be reimagined to serve modern, sleep-deprived populations.
Biology does offer some clues. Sleep is governed by two powerful systems: sleep pressure, which builds the longer we stay awake, and circadian rhythms, which respond to light and dark by telling our bodies when to release hormones like melatonin and cortisol. After lunch, a smaller rhythm called the ultradian cycle can trigger a natural dip in energy, making many of us feel sleepy. Honoring that dip with a short power nap of under thirty minutes has been linked to improved alertness and cognitive performance. But the story gets complicated when naps are longer or scattered throughout the day. Some research has linked frequent, short naps with negative health outcomes, while long afternoon naps have been associated with a higher likelihood of obesity and elevated blood sugar, a risk factor for type 2 diabetes. Al-Abri, the Omani sleep researcher, typically advises people to keep naps under half an hour. But an intriguing study of elite soccer players in Australia suggests that long naps might sometimes be useful. When researchers brought twelve male players into the lab and monitored their sleep during either one-hour or two-hour afternoon naps, they found that the athletes fell asleep in less than ten minutes. The length of the nap changed the structure of their sleep: one-hour naps contained more deep sleep, which is linked to physical recovery, while two-hour naps contained more REM sleep, which is associated with learning and memory. That hints at the possibility that shorter naps could help with recovery and longer naps with skill acquisition. As sleep researcher Anastasi Kosmadopoulos notes, sleeping in two blocks rather than one does not appear to be inherently detrimental to daily alertness or waking performance. The key, it seems, is context.
That context needs to include the person themselves. Sleep researchers are increasingly arguing that advice should be personalized rather than prescriptive. A 2025 study in Obesity looked at more than 1,200 Spanish participants and found that a person’s tendency to nap is highly heritable. The researchers quantified genetic predisposition for napping using more than a million genetic variants. People who napped against their genetic tendency—or who skipped naps when their biology suggested they should nap—showed an increased risk of obesity. Those who followed their genetic predisposition did not. This is powerful evidence that there is no universal nap prescription. The same team went on to outline eight core features that future research should measure: genetic predisposition, nap frequency, nap duration, nap timing, motivation for napping, cultural and home environment, seasonality, and overall sleep status. Each of these factors can change the meaning and effect of a nap. A nap taken by a mother of a newborn out of sheer exhaustion is not the same as a nap taken by a retired person in a hot climate as part of a cultural tradition. A nap in winter may affect the body differently than a nap in summer. A nap driven by boredom may not carry the same benefits as one driven by genuine sleep need. The field is moving away from the idea that we can simply tell everyone to sleep seven hours in one block and call it a day. As researcher João Sena Ribeiros puts it, we do not necessarily need to prove that two sleeps are better than one. What we need is to help people who cannot get their sleep in a single nighttime block get as close as possible to meeting their sleep needs, in a way that respects their biology, their culture, and their real lives.
Ultimately, the conversation about sleep needs to become more humane. For too long, napping has been framed as a sign of laziness or a failure to sleep properly, especially in cultures that prize productivity and round-the-clock availability. But human bodies are not machines, and human lives are not uniform. The mother waking at 3 a.m. to soothe a crying baby is not broken because she naps in the afternoon. The shift worker who sleeps before and after a night shift is not failing at sleep hygiene. The person who rises before dawn for prayer and returns to bed afterward is following a rhythm that has existed for centuries. The siesta is not a flaw; it is a practical response to heat and a cultural tradition worth respecting. Sleep science is finally beginning to catch up to this reality. By studying naps in all their complexity—their timing, duration, frequency, cultural meaning, and genetic underpinnings—researchers can offer guidance that actually fits the way people live. The goal should not be to force everyone into an idealized monophasic night. It should be to help every person feel as rested, healthy, and alert as possible, using patterns that work for them. Whether that means one long sleep, two sleeps, a short power nap, or a longer afternoon siesta, the answer will be personal. And that is exactly how it should be.
