Written by the Nuvirox Research Team
Key Points
- A landmark 2007 Greek study of 23,681 healthy adults found regular siesta-takers had 37% lower coronary mortality over 6+ years of follow-up.
- More recent, larger studies — including data from the Swedish Twin Registry and a UK Biobank-based systematic review — found naps of 30+ minutes associated with 11–23% higher cardiovascular risk.
- The two bodies of evidence aren't necessarily contradictory: nap duration, not napping itself, appears to be the pivot point.
Short answer: short naps look protective, long naps look risky, and the honest answer is that duration — not the siesta habit itself — is what the newer evidence keeps pointing to.
The siesta-and-heart-health story is a genuinely good example of how a single famous study becomes cultural wisdom, and how a decade of follow-up research quietly complicates it. If you've heard "napping is good for your heart," you've probably heard the 2007 version of this story. There's a more recent, less flattering chapter worth knowing too.
Where does the "napping is good for your heart" claim come from?
It traces back to a widely cited study from the University of Athens and Harvard School of Public Health, published in the Archives of Internal Medicine in 2007.1 Researchers followed 23,681 healthy Greek adults, aged 20 to 86, for an average of 6.3 years, and found that people who took a systematic siesta — napping at least three times a week for at least 30 minutes — had a 37% lower risk of coronary mortality than non-nappers. Occasional nappers saw a smaller, non-statistically-significant 12% reduction. The effect was strongest among working men, which led the researchers to a stress-relief hypothesis: a midday break may buffer the cardiovascular toll of chronic work stress.
So why do newer studies say the opposite?
Because more recent, often larger studies have zeroed in on nap duration as the variable that actually matters, and the picture there is less reassuring. A study using the Swedish Twin Registry found napping more than 30 minutes per day was associated with an 11% to 23% increased risk of cardiovascular disease compared with non-nappers.2 A broader systematic review of daytime napping and cardiovascular outcomes concluded that naps of 30 minutes or longer were linked to higher risk of all-cause mortality, cardiovascular disease, and metabolic disease, while naps under 30 minutes showed no significant association with those risks.3
Put those two bodies of evidence side by side and a pattern emerges: the original Greek study defined a "systematic siesta" as napping "at least" 30 minutes — it didn't distinguish between a 30-minute nap and a 90-minute one. Later work suggests that distinction is exactly where the risk profile flips.
Does this mean napping is bad for your heart?
Not exactly, and the evidence itself is genuinely inconsistent between regions. A 2020 case-control study out of Saudi Arabia looking specifically at siesta and ischemic stroke noted that a protective effect has historically shown up in countries where siesta is a long-established cultural habit (like Greece), while a harmful effect has turned up in countries where siesta is practiced less frequently or more irregularly, such as Israel and Costa Rica in some of the cited literature.4 That geographic split suggests napping habits may be entangled with other lifestyle and cultural variables — diet, work schedule, underlying health status — that are hard to fully separate out even in large cohort studies.
Separately, in older populations specifically, napping tells a more positive story: a study of 2,564 older adults (65+) in the Mediterranean found midday nappers scored meaningfully higher on a validated "successful aging" index than non-nappers, with the best outcomes at 8–9 total hours of sleep per day including the nap.5 Age and health status clearly interact with how napping affects the body.
What human studies actually show
Naska et al. (2007), the original Greek cohort, found a 37% lower coronary mortality risk among regular (30+ min, 3x/week) nappers versus non-nappers, in 23,681 healthy adults followed for 6.3 years, with the effect strongest in working men.1
The Swedish Twin Registry analysis found the opposite direction for naps over 30 minutes specifically — an 11–23% higher cardiovascular disease risk compared with non-nappers.2
Honest counterweight: A systematic review of napping and cardiovascular outcomes concluded that associations with diabetes, metabolic syndrome, cardiovascular disease, and mortality were, across most meta-analyses, "supported by weak or suggestive evidence" rather than strong, consistent evidence — a reminder that observational nap research is genuinely mixed and prone to confounding (people who nap long may already be sicker, more sedentary, or sleep-deprived at night for reasons unrelated to the nap itself).6
What the research doesn't settle
None of these studies are randomized controlled trials — you can't ethically or practically randomize tens of thousands of people to nap or not nap for six years. That means every finding here is observational and vulnerable to reverse causation: people with early, undiagnosed cardiovascular or metabolic disease may nap longer because they're unwell, rather than the nap itself driving the risk. This is a genuine and unresolved limitation of the entire body of napping research.
What a reasonable approach looks like
Based on where the evidence currently converges, a short nap — commonly cited as roughly 10 to 20 minutes — is unlikely to carry the cardiovascular risk signal seen with longer naps, and may offer alertness and mood benefits without much downside. If you're regularly napping 60-plus minutes and also sleeping poorly at night, that combination is worth mentioning to a doctor, since long daytime napping can be an early marker of sleep disorders or other underlying health issues, not just a cardiovascular risk factor on its own.
Frequently asked questions
Is a 20-minute power nap good or bad for my heart?
The available evidence leans toward naps under 30 minutes not carrying the cardiovascular risk signal seen in longer naps, though the research base specifically isolating short naps is smaller than the research on naps overall.
Why did the famous siesta study find naps were protective when newer ones don't?
The original 2007 study grouped all naps 30+ minutes together as a single 'systematic siesta' category, while more recent, larger studies specifically separated out longer nap durations and found the risk was concentrated there.
Does where you live affect whether napping is good or bad for you?
There's some evidence for this — countries with a long cultural history of regular, predictable siesta habits show more protective associations than countries where long napping is less routine, though this is an association, not a proven causal explanation.
Should older adults nap differently than younger adults?
Napping research in adults 65+ tends to show more consistently positive associations with successful aging measures, which may reflect different underlying sleep needs and health status in that age group.
From Nuvirox
Why we formulated Sleep+ Restore
If you're relying on a long afternoon nap to make up for a rough night, it's worth also looking at what's driving the poor nighttime sleep in the first place. Sleep+ Restore was formulated as a nightly routine builder, not a knockout dose — something to pair with the behavioral changes that the research above actually supports. We back it with a 60-day money-back guarantee, long enough to actually evaluate it the way the research says you should.
Learn more about Sleep+ Restore →If long naps have become a habit because nighttime sleep isn't cutting it, it's worth reading about whether catch-up sleep actually works the way people assume — the honest answer there has some overlap with what shows up in the napping research above. And a bedroom that's simply too warm at night is one of the more fixable reasons people end up needing a long nap to compensate.
The bottom line
Both the original protective finding and the newer risk findings are real, published, and well cited — they're just measuring somewhat different things. Short, occasional naps look fine or even mildly beneficial across most of the literature. Long, habitual naps (30-plus minutes, especially 60-plus) show a more consistent association with higher cardiovascular and metabolic risk in recent, larger studies, though causation remains genuinely unsettled. If you nap, keeping it short is the more evidence-aligned choice right now — but the honest state of the science is "it's complicated," not "solved."
References
- Naska A, Oikonomou E, Trichopoulou A, Psaltopoulou T, Trichopoulos D. Siesta in healthy adults and coronary mortality in the general population. Arch Intern Med. 2007;167(3):296–301.
- Swedish Twin Registry analysis of napping duration and cardiovascular disease risk, cited in: Napping and Siestas — Health Benefits, Risks and Best Protocols for Taking a Nap, summarizing 11–23% increased CVD risk for 30+ minute naps.
- Daytime napping and cardiovascular risk factors, cardiovascular disease, and mortality: A systematic review. Sleep Med Rev. ScienceDirect, S1087079222000958.
- Mohammad Y. Siesta and Risk for Ischemic Stroke: Results from a Case-Control Study. Medicina (Kaunas). 2020;56(5):222. DOI: 10.3390/medicina56050222.
- Midday Napping and Successful Aging in Older People Living in the Mediterranean Region: The MEDIS Study. PMC7016598. n=2,564 adults 65+.
- Association between siesta (daytime sleep), dietary patterns and metabolic syndrome in elderly living in the Mediterranean area (MEDIS study). ScienceDirect. S1279770723000969. Umbrella review noting weak/suggestive evidence overall.