Cardiovascular disease remains the leading cause of death worldwide, claiming nearly 18 million lives annually. For decades, conventional wisdom has held that regular physical exercise is the gold standard for protecting heart health. But a landmark Finnish study spanning over two decades has added a surprising contender to the conversation: regular sauna bathing. The research, led by Dr. Jari Laukkanen and his team at the University of Eastern Finland, has fundamentally changed how the medical community views the relationship between passive heat exposure and cardiovascular mortality. In this deep-dive, we'll break down exactly what the Laukkanen study found, how sauna use compares to exercise for heart health, and what the science says about combining both for maximum benefit.
The Laukkanen Study: Background and Design
Published in 2015 in JAMA Internal Medicine, the study that put sauna bathing on the global health radar was part of the Kuopio Ischemic Heart Disease Risk Factor Study (KIHD)—one of the most comprehensive population-based health studies ever conducted in Finland. Dr. Jari Laukkanen, a cardiologist and scientist at the Institute of Public Health and Clinical Nutrition at the University of Eastern Finland, led the research alongside colleagues Hassan Khan and Francesco Zaccardi.
The study followed 2,315 middle-aged men from Eastern Finland, aged 42 to 60 years, over a median follow-up period of 20.7 years. Baseline examinations were conducted between March 1984 and December 1989, and participants were tracked for sudden cardiac death (SCD), fatal coronary heart disease (CHD), fatal cardiovascular disease (CVD), and all-cause mortality events. What makes this study particularly noteworthy is its sample population: in Finland, sauna bathing is so culturally ingrained that only 12 of the original participants reported not using a sauna at all—meaning the "low frequency" control group still consisted of men who used the sauna once per week, not zero times.
Participants were divided into three groups based on how frequently they used a traditional Finnish sauna: once per week (601 men), two to three times per week (1,513 men), and four to seven times per week (201 men). The sauna sessions were conducted at an average temperature of approximately 174°F (79°C), with a typical session lasting around 20 minutes.
Key Findings: The Numbers That Changed Everything
The results were striking and dose-dependent—meaning the more frequently men used the sauna, the greater the protective effect observed. After adjusting for known cardiovascular risk factors including age, body mass index, systolic blood pressure, cholesterol levels, smoking status, alcohol consumption, previous heart attacks, physical activity level, and socioeconomic status, the data revealed dramatic reductions in cardiovascular mortality for frequent sauna users.
Men who used the sauna four to seven times per week experienced a 63% lower risk of sudden cardiac death compared to those who bathed only once per week. The risk reductions for fatal coronary heart disease and fatal cardiovascular disease were 48% and 50%, respectively. Perhaps most remarkably, all-cause mortality—death from any cause—was 40% lower in the most frequent sauna users. Even moderate use of two to three sessions per week showed meaningful reductions across all endpoints.
Session duration mattered as well. Men who spent more than 19 minutes per session in the sauna experienced a 52% lower risk of sudden cardiac death compared to those whose sessions lasted fewer than 11 minutes. Similar duration-dependent reductions were observed for coronary heart disease and cardiovascular disease mortality. For those wondering about the ideal amount of time, our guide on how long you should sauna covers this in detail.
How Sauna Bathing Mimics Exercise on the Heart
One of the most fascinating aspects of the Laukkanen research—and the broader body of heat therapy science—is the degree to which sauna bathing mirrors moderate-intensity cardiovascular exercise at the physiological level. As Dr. Laukkanen himself has noted, the cardiovascular responses produced during a typical sauna session are remarkably similar to those seen during moderate to high-intensity physical activity.
During a sauna session, your heart rate can increase from a resting rate of around 60–80 beats per minute to between 120 and 150 beats per minute—a range comparable to moderate aerobic exercise like brisk walking or light jogging. This elevated heart rate increases cardiac output, forcing the heart to pump more blood with each beat. Unlike exercise, however, there is no active skeletal muscle contraction involved. Instead, the heat causes blood vessels to dilate (vasodilation), redirecting blood flow from internal organs to the skin's surface to dissipate heat. This process decreases peripheral vascular resistance and lowers blood pressure, both acutely during the session and, with regular use, chronically over time.
A 2018 review published in the Mayo Clinic Proceedings by Laukkanen and colleagues outlined several proposed mechanisms through which sauna bathing benefits heart health. These include improved endothelium-dependent vasodilation (the ability of blood vessel walls to relax), reduced arterial stiffness, modulation of the autonomic nervous system toward parasympathetic dominance, beneficial changes in circulating lipid profiles, lower systemic blood pressure, and decreases in inflammatory markers like C-reactive protein and fibrinogen.
Sauna vs. Exercise: Head-to-Head Comparison
So if sauna bathing produces many of the same cardiovascular responses as exercise, does that mean it can replace your workout? The short answer is no—but the nuance is important, and the data suggests the relationship between the two is complementary rather than competitive.
Exercise provides benefits that a sauna simply cannot replicate. Physical activity strengthens skeletal muscles, improves bone density, enhances metabolic efficiency, burns calories through active energy expenditure, and provides neurological benefits through the complex coordination of movement. A sauna session, by contrast, is a passive intervention—your muscles aren't working, your bones aren't being loaded, and your caloric expenditure, while modestly elevated, doesn't approach what you'd burn during a run or weight training session.
Where sauna bathing shines, however, is in its cardiovascular and vascular benefits—particularly for individuals who may have difficulty exercising. A 2021 cross-over study by Lee, Kostensalo, Willeit, and Laukkanen compared standalone sauna bathing to a combination of exercise followed by sauna in 72 participants with at least one cardiovascular risk factor. The researchers found that when matched for duration, both interventions produced comparable acute hemodynamic changes, including reductions in blood pressure and improvements in arterial compliance. The study concluded that sauna use may be a viable lifestyle treatment option for blood pressure management in those who cannot perform aerobic exercise.
This finding has enormous implications for the elderly, individuals recovering from injury, people with mobility limitations, and anyone for whom traditional exercise is difficult or impossible. If you're exploring options for improving your overall health through sauna use, the science supports it as a legitimate cardiovascular intervention—not just a luxury.
The Combined Effect: Exercise Plus Sauna
Perhaps the most exciting finding from the Laukkanen research group involves the combined effect of exercise and sauna bathing. In a follow-up analysis, Kunutsor, Khan, and Laukkanen examined the joint associations of cardiorespiratory fitness and sauna bathing frequency on cardiovascular and all-cause mortality risk. The results demonstrated that combining high fitness levels with frequent sauna use provided substantially greater protection than either intervention alone.
A 2022 multi-arm randomized controlled trial by Lee, Kolunsarka, and Laukkanen further explored this relationship. Participants were assigned to either exercise combined with post-exercise sauna sessions, exercise alone, or a control group for eight weeks. The combination group showed improvements in blood pressure and cardiorespiratory fitness, suggesting that the two interventions work through complementary pathways to improve cardiovascular function.
Even participants with low fitness levels showed reduced mortality risk when they combined whatever activity they could manage with regular sauna sessions. However, mortality risk dropped most dramatically in those with high fitness levels who also used the sauna frequently. This dose-response relationship across both modalities reinforces the idea that sauna bathing isn't just a substitute for exercise—it's a powerful addition to it. If you're interested in optimizing both, our article on athletes and saunas covers how active individuals can incorporate heat exposure into their training.
Beyond Cardiovascular Health: Additional Findings from the KIHD Cohort
Dr. Laukkanen's research didn't stop at cardiovascular mortality. Subsequent analyses of the same Finnish cohort—and a later study including 1,688 men and women with a median follow-up of 15 years—have revealed additional protective associations of frequent sauna bathing.
A 2017 study in the American Journal of Hypertension found that regular sauna use was associated with a reduced risk of developing hypertension. Separate analyses demonstrated reduced risk of stroke, and a particularly notable 2017 paper in Age and Ageing found that men who used the sauna four to seven times per week had a 66% lower risk of developing dementia and a 65% lower risk of Alzheimer's disease compared to those who used it once per week. Research has also linked frequent sauna bathing to reduced risk of pneumonia and other respiratory conditions, lower levels of systemic inflammation, and improved risk prediction when sauna habits are added to conventional cardiovascular risk models.
A 2018 study that expanded the cohort to include women confirmed that the protective effects of sauna bathing on cardiovascular mortality were not limited to men. The risk of fatal CVD decreased linearly with increasing sauna sessions per week with no threshold effect, meaning there was no "diminishing returns" point within the ranges studied. This broader understanding of sauna's health impact has implications for everything from blood pressure management to diabetes management through sauna therapy.
Important Caveats and Limitations
While the Laukkanen study is among the most robust and widely cited in sauna research, it's essential to approach the findings with appropriate scientific nuance. First, this was an observational study, not a randomized controlled trial. While the researchers adjusted for numerous confounding variables including physical activity, BMI, smoking, alcohol, cholesterol, and socioeconomic status, observational studies cannot definitively prove causation. It's possible—though the researchers argue it's unlikely—that some unmeasured factor associated with frequent sauna use could partially explain the results.
Second, the original 2015 study included only middle-aged men from Eastern Finland—a population with lifelong familiarity with sauna culture. While the 2018 follow-up study included both men and women with similar findings, the generalizability to other populations, ethnicities, and cultures still warrants further investigation.
Third, the study specifically examined traditional Finnish sauna bathing at temperatures around 174°F (79°C) with the ability to throw water on heated rocks for steam. It was not conducted using infrared saunas, steam rooms, hot tubs, or other forms of heat therapy. While infrared saunas and other modalities may provide overlapping benefits—and some research supports this—the specific mortality reductions cited in the Laukkanen study apply to traditional sauna use. If you're deciding between different sauna types, our guide on the healthiest form of sauna can help you understand the differences.
What This Means for Your Sauna Practice
For those looking to apply the Laukkanen findings to their own wellness routine, the practical takeaways are clear. Frequency matters most: aim for at least two to three sauna sessions per week, with four to seven sessions providing the most significant benefits observed in the study. Duration also plays a role—sessions of 19 minutes or longer were associated with greater risk reduction than shorter sessions. The sauna temperature in the study was approximately 174°F (79°C), consistent with typical traditional sauna temperatures.
For a more detailed breakdown of session frequency, our science-backed guide to optimal sauna frequency walks through recommendations based on experience level and health goals. Dr. Andrew Huberman, the Stanford neuroscientist, has also developed his own evidence-based sauna protocol—we've covered that in our article on Dr. Huberman's stance on saunas and deliberate heat exposure.
If you're looking to combine sauna and cold therapy for additional benefits, contrast therapy—alternating between heat and cold exposure—has its own growing body of supportive research. You can explore our full contrast therapy collection of saunas and cold plunges to build a comprehensive home wellness setup.
Building Your Home Sauna Routine
The Laukkanen study, along with the broader body of evidence it inspired, makes a compelling case for regular sauna use as part of a proactive health strategy. Whether you're a competitive athlete using heat exposure for performance and recovery, someone managing cardiovascular risk factors, or simply a wellness-minded individual looking to invest in your long-term health, adding a sauna to your home eliminates the barriers of access and scheduling that often prevent consistent use.
For a traditional sauna experience that most closely mirrors the conditions in the Laukkanen study, a traditional Finnish sauna with a quality sauna heater package is the way to go. If you prefer a gentler heat experience or have space and electrical constraints, an infrared sauna offers many of the same cardiovascular benefits at lower operating temperatures. For maximum versatility, a hybrid sauna combines both traditional and infrared heating in a single unit. If you want the full DIY experience, our DIY sauna kits provide everything you need to build a custom sauna in your home.
No matter which type of sauna you choose, the science is increasingly clear: consistent, frequent sauna bathing is one of the most accessible and evidence-backed lifestyle interventions available for protecting your cardiovascular system. It doesn't replace exercise—but combined with it, the results are greater than either alone. Our comprehensive guide on the best sauna for your home can help you find the right fit for your space, budget, and wellness goals.
The Bottom Line
The Laukkanen study didn't prove that sauna bathing is a replacement for exercise—but it did something arguably more important. It demonstrated, with two decades of rigorous population-level data, that regular sauna use is independently associated with dramatic reductions in cardiovascular death and all-cause mortality. The physiological mechanisms overlap significantly with those of moderate-intensity exercise: improved vascular function, lower blood pressure, reduced arterial stiffness, decreased inflammation, and enhanced autonomic regulation. When combined with regular physical activity and good cardiorespiratory fitness, frequent sauna bathing provides compounding protection that neither intervention achieves alone.
For the millions of people worldwide at risk of cardiovascular disease—and for those simply interested in living longer, healthier lives—the message from Finland is clear: the sauna isn't just a place to relax. It's a place to protect your heart.
*Haven Of Heat and its affiliates do not provide medical, legal, electrical, building, financial, or professional advice. All content published on this website is for general informational and educational purposes only and should not be relied upon as a substitute for advice from qualified professionals. Always consult a licensed medical provider regarding health-related questions. Individual results from sauna use may vary. No health or performance outcomes are guaranteed.
References
- Laukkanen, T., Khan, H., Zaccardi, F., & Laukkanen, J. A. (2015). Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Internal Medicine, 175(4), 542–548. PubMed
- Laukkanen, J. A., Laukkanen, T., & Kunutsor, S. K. (2018). Cardiovascular and other health benefits of sauna bathing: A review of the evidence. Mayo Clinic Proceedings, 93(8), 1111–1121. PubMed
- Laukkanen, T., Kunutsor, S. K., Khan, H., Willeit, P., Zaccardi, F., & Laukkanen, J. A. (2018). Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: A prospective cohort study. BMC Medicine, 16, 219. PMC
- Lee, E., Kostensalo, J., Willeit, P., et al. (2021). Standalone sauna vs exercise followed by sauna on cardiovascular function in non-naïve sauna users: A comparison of acute effects. Health Science Reports, 4(4), e393. PubMed
- Lee, E., Kolunsarka, I., Kostensalo, J., et al. (2022). Effects of regular sauna bathing in conjunction with exercise on cardiovascular function: A multi-arm, randomized controlled trial. American Journal of Physiology—Regulatory, Integrative and Comparative Physiology, 323(3), R289–R299. APS Journals
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