Heart Health and Heat: What You Need to Know About Infrared Saunas and Cardiovascular Support

Infrared saunas have surged in popularity as a wellness trend, but their appeal goes beyond relaxation. Emerging science suggests that basking in these gentle heat chambers may benefit your heart and blood vessels. How does sitting in a warm, infrared-lit room support cardiovascular health? Let’s explore what the research reveals.

How Infrared Saunas Work (and Why They Feel Different)

Infrared vs. Traditional Sauna: An infrared sauna is a type of sauna that uses special light waves (far-infrared, sometimes accompanied by near-infrared and mid-infrared) to heat your body directly, instead of super-heating the air around you [1]. Traditional Finnish-style saunas warm the air to about 175°F (80°C+) and can feel intensely hot. Infrared saunas, by contrast, operate at a more comfortable ~140°F (60°C), yet still make you sweat profusely. The infrared light penetrates deeper into the skin to raise core body temperature without the stifling air temperature [2]. In practical terms, many people find infrared saunas easier to tolerate if they “can’t stand the heat” of a classic sauna [3].

Mimicking Moderate Exercise: Stepping into an infrared sauna might not feel like exercise at first, but your body soon reacts as if you’re doing a light cardio workout. Your heart rate rises and you begin to sweat, similar to the effects of brisk walking or jogging [4]. In fact, maintaining your core temperature in the heat triggers a cascade of cardiovascular responses – blood vessels dilate (widen), the heart pumps faster, and cardiac output increases – comparable to what happens during moderate-intensity exercise [5][6]. One review noted that the cardiovascular demand of an infrared sauna session is “similar to that achieved by walking at a moderate pace” [7]. This exercise-mimicking effect is great news for people who are sedentary or have joint issues preventing regular exercise: a sauna session can give your heart a gentle workout while you sit and relax.

Lower Blood Pressure Through Passive Heat

One of the most touted heart benefits of sauna therapy is its effect on blood pressure. When your body heats up in an infrared sauna, your blood vessels respond by widening (a process called vasodilation). This expansion of the vessels causes blood to flow more easily and reduces overall vascular resistance – in plain language, it can lower blood pressure. Think of it as giving your arteries a chance to relax and open up, which takes strain off the heart. In fact, clinical studies have found that regular sauna use can help normalize high blood pressure. In a 2009 review of published evidence, researchers concluded there was “moderate evidence” that far-infrared sauna therapy can normalize blood pressure in those with hypertension [8].

More recent studies back this up with hard data. For example, in one small trial, people with cardiovascular risk factors underwent 15-minute infrared sauna sessions daily for two weeks. The results showed a drop in blood pressure – systolic blood pressure went from about 107 mmHg on average to 97 mmHg after the sauna therapy [9]. Importantly, no adverse effects were noted; the participants actually reported feeling better overall. Another study of patients with peripheral artery disease (a circulatory condition) found that a course of heat therapy not only reduced blood pressure but also improved blood flow to the legs [10]. These findings echo what cardiologists have observed anecdotally – as Harvard Heart Letter editor Dr. Thomas Lee puts it, “sauna lowers blood pressure, and there is every reason to believe that its effects are good for blood vessels” [11].

Why Blood Pressure Drops: The mechanism for this blood-pressure lowering is straightforward. Heat causes vasodilation, which means your arteries and veins widen. Wider, more relaxed vessels means blood flows with less resistance, so your heart doesn’t have to push as hard to circulate blood. This is akin to how exercise lowers blood pressure by making blood vessels more elastic. Additionally, as you sweat in the sauna, your body sheds some fluid and this can temporarily reduce blood volume, contributing to a lower pressure reading. Over time, repeated sauna sessions might train blood vessels to remain more supple and improve their ability to dilate. The net effect is a gentle, drug-free way to help manage hypertension or simply keep your blood pressure in a healthy range.

Boosting Circulation and Vascular Health (Endothelial Function)

Infrared saunas are not just about blood pressure; they also improve circulation and the health of your blood vessels in ways that support overall cardiovascular function. When you sit in the soothing heat, your heart rate can climb into the 100–150 beats per minute range, effectively pumping more blood with each minute [12]. This increased circulation is why many people report a pleasant “glow” or muscle relaxation after a sauna – your muscles and skin are literally getting more blood flow.

A key part of healthy circulation is the endothelium, the delicate inner lining of blood vessels. The endothelium helps vessels dilate and constrict as needed, and it releases signaling molecules (like nitric oxide) to regulate blood flow. Many cardiovascular diseases begin with endothelial dysfunction – basically, blood vessels that can’t dilate properly. Sauna bathing appears to directly benefit endothelial function. Research has shown that regular infrared sauna sessions improve endothelium-dependent dilation of arteries [13]. In the trial mentioned earlier, not only did blood pressure drop, but ultrasound measurements of the participants’ arteries showed significantly better dilation capacity after two weeks of sauna therapy [9].

Why does this happen? The heat stress from a sauna session prompts the endothelium to produce more nitric oxide, a natural compound that tells blood vessels to relax. In one study, scientists found that passive heat therapy boosted nitric oxide–dependent blood vessel dilation in sedentary adults, improving their microcirculation [14]. Another study in 2016 demonstrated improvements in arterial stiffness (making arteries more pliable) and enhanced endothelial function after a program of repeated heat sessions [15]. Reduced arterial stiffness is good news for your heart – stiffer arteries make the heart work harder, so more flexible arteries lighten the cardiac workload. By improving these factors, infrared saunas may help prevent atherosclerosis (hardening of arteries) or slow its progression [15]. In fact, Japanese doctors have used a form of infrared sauna therapy (sometimes called “Waon therapy”) for patients with heart failure and found it improved their blood vessel function and exercise capacity [16]. All of this points to infrared saunas as a boon for your vascular health, essentially giving you the blood vessels of a more active person.

Heart Rate, Conditioning, and Heart Rate Variability (HRV)

Ever notice how your heart pounds a bit after you’ve been in a sauna for a while? This increase in heart rate isn’t a cause for concern – it’s actually part of the therapeutic effect. In an infrared sauna session, heart rates commonly reach 120–150 beats per minute, similar to light-to-moderate exercise [17]. This means your heart is working a bit harder, which over time can strengthen your cardiovascular system.

Heart rate variability (HRV) refers to the slight variations in time between each heartbeat. Generally, higher HRV is associated with better cardiovascular fitness and a more resilient autonomic nervous system. Interestingly, sauna use can influence HRV in beneficial ways. When you’re sitting in the intense heat, your body activates the sympathetic nervous system (similar to exercise), which might temporarily lower HRV. But during the cooling-off period after the sauna, there’s often a rebound activation of the parasympathetic (relaxation) side, which increases HRV as you recover.

Research indicates that repeated heat exposure leads to improved autonomic regulation of the heart. In one report, short-term heat training (over 4–14 days) induced adaptations including better cardiac autonomic modulation as measured by HRV [18]. Another study by Finnish researchers noted that the cooling-down phase after a sauna saw a significant rise in HRV, reflecting a shift into a deeply relaxed, parasympathetic state [19]. By regularly nudging your autonomic nervous system through these heat-and-cool cycles, you might improve your vagal tone and stress resilience over time. Many athletes and biohackers have started monitoring their HRV and report that sauna sessions improve their numbers, indicating a positive effect on recovery and overall heart health [20]. While more research is ongoing, the existing evidence suggests infrared saunas help balance your nervous system, which is a cornerstone of cardiovascular wellness.

Real-World Evidence: A Heart-Healthy Habit 

Saunas aren’t just laboratory experiments – millions of people use them regularly, and population studies give us insight into their long-term benefits. One striking example comes from Finland, where sauna bathing is a way of life. In a 20-year study tracking about 2,300 middle-aged Finnish men, researchers found that frequent sauna users had markedly lower risks of fatal heart problems and even all-cause death [21]. Men who enjoyed sauna sessions 4–7 times per week were much less likely to die from heart disease or stroke compared to those who used the sauna only once a week [21]. In fact, the most frequent sauna-goers had about a 50% lower rate of fatal heart events over those two decades.

While correlation doesn’t always equal causation, the researchers believe sauna’s positive effects on blood pressure, vascular function, and stress reduction play a role in this longevity boost. It’s telling that sauna use was an independent predictor of survival even when accounting for other factors – suggesting that regular heat therapy is a heart-healthy habit akin to exercise or a good diet.

What about safety? The idea of sitting in 140°F heat might sound intense, especially if you have a heart condition. Fortunately, studies and clinical experience show that infrared saunas are generally well-tolerated and safe for most people, even those with stable heart issues. Unlike high-humidity steam rooms and, infrared saunas’ gentler temperature is less likely to cause blood pressure swings or extreme strain. In clinical trials with heart patients (including people with congestive heart failure), participants typically handle sauna sessions without trouble – no harmful effects have been reported with infrared saunas in the medical literature [22]. In fact, patients often experience improved symptoms. A systematic review in 2018 found that sauna bathing was safe and potentially beneficial for people with mild heart failure [23]. Doctors do note a few caveats, though. If you have unstable angina, recent heart attack, or very low blood pressure, extreme heat exposure might not be advisable [24].

Conclusion

The bottom line is that infrared saunas offer a warm path to better heart health. By inducing effects similar to exercise, they help lower blood pressure, improve circulation, make blood vessels more flexible, and balance the autonomic nervous system in ways that may increase heart rate variability and stress resilience. Peer-reviewed studies have demonstrated improvements in endothelial function and overall cardiovascular performance with regular sauna use, supporting the idea that this age-old heat therapy is more than just a relaxing ritual – it’s a boon for your heart and arteries [13][15]. Real-world evidence from habitual sauna users further reinforces these benefits, with associations to longer, healthier lives. All of this comes without having to lift a weight or jog a mile; you simply sit and let the heat work its magic.

Of course, saunas aren’t a cure-all. Think of them as one tool in a heart-healthy lifestyle toolkit, complementing exercise, a balanced diet, and medical care when needed. From healthier blood pressure and arteries to a well-tuned nervous system, the gentle power of infrared heat can support your cardiovascular system in remarkable ways.

References

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22. Imamura M, et al. Circulation Journal. 2001;65(7):587–592.

23. Laukkanen T, et al. Age Ageing. 2017;46(2):245–249.

24. Harvard Health Publishing. Sauna safety tips.