3 Acute Effects Of Sauna Bathing On Cardiovascular Function

*Disclaimer: The written article is based on a summary of existing scientific literature on the topic of infrared saunas. The article is for educational purposes and the information provided below cannot be taken as a promise to help with acute health problems or diseases.

The claims in the article are backed by 25 scientific references. All references are numbered. You can access the text of the reference by clicking on the number.

"Cardiovascular function", or, "blood vessel and heart health", has become increasingly important in today's society. With people getting older, issues with heart and blood vessels have become either the leading or the second cause of death worldwide (1; 2; 3).

This blog post does not explore that topic! Instead, we'll look at acute effects of sauna bathing on cardiovascular function - i.e. how do your heart, nervous system, and other parts of your body respond to sitting in a sauna immediately after you get in. In other words, I tell you what to expect immediately after getting in a sauna.

Let's find out:

Effect 1: Lowering Blood Pressure By Up To 7 Points

Using a sauna and cardiovascular health's most important effect is perhaps that of lowering blood pressure (4; 5). 

In essence, your heart changes its rhythm, and blood flow speed from the upper part of your body to the lower parts decreases by 33%. Systolic blood pressure, moreover, decreased by 7 points, from an average of 127 in the study participants to 120. Diastolic blood pressure had a similar reduction of 7 points, going from 82 to 75. 

If you don't know these terms, systolic pressure is how strongly your blood presses against artery walls when your heart is beating. Diastolic pressure occurs when your heart is resting.

Even 30 minutes after using a sauna, that systolic pressure remains low. 

Also, overall heart rate increases by up to 70 beats per minute, meaning that's it's a short-term stressor on your body. Exercise is similar in that regard.

Why care about blood pressure?

Well, hypertension, or high blood pressure, is one of the strongest predictors of cardiovascular disease, in the long term (6; 7; 8). There's reasonably strong evidence that sauna bathing also lowers hypertension risk (9; 10).

Effect 2: Boosting Circulation, Specifically Your Smallest Blood Vessels

The second of the effects of sauna on cardiovascular function is an increase in circulation. Why? Well, remember that your heart rate dramatically increases when you spend a long time in a sauna. In that way, using a sauna is similar to engaging in a quick-paced walk (11; 12; 13).

In relation to the decrease in the speed of circulation and blood pressure, the heart pumps much harder to compensate. Blood flow to the organs in your stomach also goes down, while blood flow to the extremities increases. That blood flow pattern is supportive of allowing your body to sweat more efficiently.

In time, moreover, overall circulation also improves if you consistently hit the sauna every week - preferably a few times a week!

And even though the scientific evidence isn't yet fully convincing, it's reasonable to hypothesize that sauna use also increase your microcirculation. 

With "microcirculation" I mean the very tiny blood vessels that exchange nutrients and toxins with your cells. These blood vessels are called "capillaries", and through exercise and potentially also sauna use you can increase the density of these blood vessels.

I will say that this blood circulation benefit is not immediate, although, the improvement in overall circulation is. For the best effects, consistent sauna use is best!

Effect 3: Long-Term Overall Cardiovascular Disease Mitigation

So you might think: what are the long-term effects of these previous two benefits? "How good is sauna for your cardiovascular health?"

Let me explain:

Sauna use lowers your overall cardiovascular risk through many more mechanisms than the ones I just described. For instance, according to an excellent systematic review from 2018 (14):

"The beneficial effects of sauna baths on [cardiovascular disease] and mortality may be mediated via reduction in blood pressure, improvement in endothelial function, reduction in oxidative stress and inflammation, beneficial modulation of the autonomic nervous system, improved lipid profile and arterial compliance, and improvement in the cardiorespiratory system."

Here's what these words mean in plain English:

• Blood pressure is lowered and circulation improves, as you already know
• "Oxidative stress" is lowered. Oxidative stress is the presence of "free radicals", which are byproducts of energy production (but also stress). These free radicals are almost certainly one of the factors contributing to aging.
• Inflammation is also lowered. Some inflammation is healthy but excess inflammation is linked to many different chronic diseases, including heart and blood vessel conditions (15; 16; 17).
• "Modulation of the autonomic nervous system" means that you'll find a better balance between stress and relaxation. Many people are chronically stressed in the modern world, and adding more relaxation - such as spending time in an infrared sauna - can swing the pendulum back towards more balance. Chronic stress is also very specifically tied to heart health (18; 19). And to go one step further, yes, all those type-A patients are more prone to have issues with their heart and blood vessel health (20; 21)!
• Your "lipid profile" is also one of the predictors of heart disease (22; 23). The related cholesterol theory is not universally accepted in the holistic and natural health community. And yet, sauna exposure does affect your lab numbers!
• Lastly, the "cardiorespiratory system" is the interaction between your lungs and heart health. Simply put, the better your lungs and respiration in general work, the more your risk for blood and circulatory issues goes down (24; 25). There's also literally interaction between the lungs and heart, for instance, because of pressure in the chest and other very complex means.

But let's simplify my message again...

What's the bottom line?

The current science shows that sauna use is extremely good for your overall heart and blood vessel health. Many of these variables have not been studied insofar whether they improve immediately after one session. But, because blood pressure and circulation change in the short term as well as long term, it's reasonable to hypothesize that "oxidative stress" and "inflammation" also improve after just one session!

Let's therefore conclude:

Conclusion: Become Fantastic, Not A Statistic!

So here's the deal:

As many as 1 in 3 people in developed countries die due to heart and blood vessel issues nowadays or have a chronic condition that drastically lowers their overall health.

And sure, saunas aren't a "magic cure". If you insist on drinking sugar-laden soda every single day, don't move much, rarely prioritize sleep, and generally eat unhealthy, a sauna is not going to fix your issues.

Nevertheless, a sauna - especially a premium-quality infrared sauna - will become a very important tool to move the needle into the right direction! 

Generally, the research shows that the more days you use your sauna each week, the better your overall heart and blood vessel health becomes. 

As always, there are exceptions to the rule! If you currently have a (chronic) heart or blood vessel problem, always consult with your physician first before using (intense) sauna sessions. You absolutely need clarity from your doctor that your cardiovascular and respiratory system can take some pressure before you commit to a 30-minute sauna session.

I hope that recommendation is common sense but I'm including it anyway...

My final message?

Don't become part of that 1 in 3 statistic. Start upgrading your health routines today, avoid sugar-rich soda, move around a lot, eat healthy, and add a sauna to that toolbox. And if you're getting a sauna anyway, you might as well get the best.