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How Saunas Boost Cardiovascular Health: An Interview with Dr. Earric Lee

How Saunas Boost Cardiovascular Health: An Interview with Dr. Earric Lee

Jillian Le |

Table of Contents

Introduction

Saunas have long been celebrated for their health benefits. They're known to help with muscle relaxation, skin cleansing, headache relief, immunity boost, deep sleep, and more. However, concrete scientific proof about these benefits, especially regarding the heart, has been sparse. Now, a study from Finland is shedding light on how saunas can positively impact our cardiovascular health.

Back in the 1940s, researchers believed that saunas might boost various heart functions, which could lead to overall health improvement. But since then, there's been a concerning rise in cardiovascular diseases, partly because many people aren’t active enough to reap the health advantages of regular exercise.

The challenge? A large number of people either lack the motivation or the necessary fitness levels to engage in exercises that could improve their heart health. This scenario highlights the need for alternative methods to promote cardiovascular wellness.

Enter the sauna. New findings suggest that combining sauna sessions with exercise can enhance heart health more than just exercising on its own.

This research, spearheaded by Dr. Earric Lee from the University of Jyväskylä, was featured in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology.

Timestamps:

  • 00:44: How Earric Got Interested In Sauna
  • 02:27: Background on Earric's Research In to Sauna
  • 03:44: How Sauna Affects the Cardiovascular System
  • 06:07: Advice for People New to Sauna
  • 02:16: Results of Earric's Sauna Research

Beginning Of Interview

Hi, this is Nate from Harvia Sauna and Spa. Today we're talking with Earric Lee, researcher at the University of Jyväskylä, who specializes in cardiovascular health and sauna use. In this interview, we touch on topics such as cardiovascular health, exercise, the benefits of sauna, the connection between all three, as it's supported by his most recent research.

Nate: Earric, welcome to Harvia.

Earric: Thank you very much.

We've got some time here for an interview with you. And we've heard all about some of the research that you've done with sauna, some of the research you've collaborated with Jyväskylä university here.

Why don't you start from the beginning and tell us a little bit how you started getting interested in Saunas and the research that you do with the cardiovascular system?

Ok, so I'll answer the first question how I got started with the sauna. Well, there's two parts to it. The first part is when I was a competitive athlete, I used to use the sauna a lot.

Mostly for making weight, so trying to get some water weight off my body. Subsequently, I moved into more serious training. I was still a competitive athlete, but my training had a, was a bit too strenuous, so it had a very disturbing effect on my muscles.

I had these very severe cramps, especially on my legs, so my quads and my hamstrings. And I would have a cramp on my vastest medialis, which is the muscle closest to the knee if I extended my leg.

So I couldn't extend my leg. So I had to flex my knee and when I flex my knee, my hamstrings would cramp and I had to walk like that because if I bend my knee too much, then my hamstrings were going to cramp. If I straighten my knee too much, my quads are going to cramp. That happens whenever I had a strenuous workout.

So one of the suggestions that my coworkers at the time suggested to me was to use the sauna after training. He claimed that it would help. And I said OK. Let's give it a shot and it did. It did for at least 30 minutes after the sauna.

It was not cramping up. How I got into cardiovascular Physiology and the sauna was a bit of a serendipity.

So, I wasn't sure what kind of sauna research was being done when I wanted to do it, but I was told that my present supervisor, doctor Jari Laukkanen, he was working towards publishing research about the sauna at the time when I met him.

So, he roped me in, not knowing that I was already interested in the topic and of course, the discussion was short and when he gave me the suggestion, would you like to do research regarding the Saunas since you're interested in cardiovascular Physiology? Which is primarily my passion and my area of interest, I jumped on it, and I said yes, sure, of course.

Short discussion, couple of papers later, you know we've achieved quite a lot of, we've acquired a lot of additional knowledge that we pulled together to help in my opinion, try to advance the field of Sauna and cardiovascular Physiology studies.

How does the sauna perhaps make an impact for the average person with an average non-athlete type cardiovascular system?

A lot of the research on the effects of the sauna isn't conducted on the average population, which is the problem we're facing in the field.

So they've seen positive effects, right? But then we have seen positive effects of heat therapy using the sauna on the extreme ends of the population.

So we talk about very sick people, the clinical population, those with chronic heart failure.

Rest of the research that has been done that I mentioned earlier, they were done on athletic population, right?

So then that is on the other end of the spectrum. And so the research that I've just published recently is one step toward understanding what we're going to do with using the sauna and how we can best try to exploit.

I would use the word exploit the different variables that we can modify in sauna usage to give the average person the best benefit.

So coming back to that first question for the average person now it's important to understand that the body adapts to stress, any kind of stress, as long as if it's exerted on the physiological system.

So for the average person, I usually would suggest that if they're just starting out using the sauna, they could maybe use it for once a week for the first one to three weeks and then after that, increase it to twice a week and then subsequently increase it to three times a week.

The number of bouts is up to the individual. Some people do 4, some people do six, you know.

I usually do about three, about two or three. I get comfortable.

Yeah, yeah. Yeah, exactly. So that's like three or four has been touted to be something that's comfortable for the average person.

Now, bearing that in mind, if you do that and you stick to doing that, then you have less things to sort of like monitor. You know what I mean?

So then you could go OK, I'll go once a week, 3 bouts, you know, every time I'm there, I'll just do 3 bouts.

OK now I'm going to go twice a week, OK, but I'm still doing 3 bouts, and that way you can increase the amount of stress. That's one way.

The next way would be to keep the same number of times you visit sauna. So once a week, right? But then over time say over the course of again two to three weeks later, increase the number of bouts you go to. So instead of three, you go four.

Then you go 5, then you go six, you know, and then because that creates sort of like an additional level of heat stress for the system to adapt to.

Could you give us a summary or like a too long didn't read version of the results of your study?

Sure. So compared to exercise. Exercise plus sauna regularly, both of them, regular exercise plus regular sauna confers more benefits and these benefits are seen via the increase or there's more increase in VO2 Max compared to just exercise. Exercise also increases VO2 Max, but not to the extent that exercise plus sauna gives, and it decreases blood pressure, particularly systolic blood pressure.

In the study, we didn't find that exercise reduced any of the blood pressures that we measured, but exercise plus sauna, there was a reduction in systolic blood pressure and also we could say the same for total cholesterol levels. It was also reduced, whereas with exercise we didn't see that reduction.

Ok, and again, these participants that you had were average, relatively sedentary?

Sedentary; it's very important to highlight that they were not only sedentary, but they also did not go to the sauna often these are people who do not use the sauna frequently.

I make that I make that point, particularly because there's been a lot of criticism for the studies that we've conducted earlier, that the reviewers have said that, oh, how do we know these results are going to be found can be found in the regular population? Because the research that you've conducted on, are on the finished population who goes to the sauna more frequently.

So maybe these results are only seen because they go to the sound irregularly, their body has adapted.

So we sort of made sure that in this study the the participants in this most recent study, they are sauna naive.

Just based on my understanding of science, there is a ceiling, IE there is a point of diminishing returns.

You'll get to a point where doing more sauna will not necessarily give you additional benefit, but there's also a floor. There is a minimum.

For instance, I'm going to go out on a limb and say this. It's all speculation, we'll have to do some research to find out, but I'm pretty sure that the floor is probably twice a week; going to the sauna, twice a week.

Now you can quote me, but I have no research to back me up. We do have some research that has shown that going to the sauna twice a week is effective for other things such as chronic tension headache and also for reduction of incidence of colds.

But that's not where my postulation comes from because I'm if we were to look at exercise as something that's comparable to the sauna or actually the other way around, if we were to look at sauna that's comparable to exercise, then what's recommended is to exercise two to three times a week, right?

The bare minimum. If you exercise if you exercise twice, then you probably have to up the intensity of your exercise. If you exercise three times, then you probably keep it at a moderate level.

Therefore, in that same way, you'd subject your body to that amount of heat stress as well. That's how I kind of established that relationship. Yeah, yeah, that's how I think about it.

But you're the expert, so you can make those kind of postulations right?

Oops. (Laughing)

Key Takeaways:

  • Earric Lee's journey into sauna research began with his own personal experience as an athlete, where saunas provided relief from muscle cramps following strenuous workouts.
  • Driven by his interest in cardiovascular physiology and a serendipitous encounter with Dr. Jari Laukkanen, Lee became involved in pioneering research that bridged the gap between sauna use and cardiovascular health.
  • While much of the research has been focused on the extremes (athletes and those with chronic heart conditions), saunas offer benefits to the average individual, especially those leading a sedentary lifestyle.
  • For those new to saunas, Eric recommends starting with a session once a week, then gradually increasing the frequency and duration over time, ensuring the body adapts to the heat stress.
  • Lee's study found that combining regular exercise with regular sauna sessions resulted in a greater increase in VO2 Max than exercise alone. It also showed reductions in systolic blood pressure and total cholesterol levels, factors not observed with exercise only.
  • It's important to note that participants in the study were 'sauna naive', meaning they were not regular sauna users, ensuring the results were applicable to a wider audience.
  • Lee postulates (though emphasizes more research is needed) that there might be a 'floor' for optimal sauna use, potentially around twice a week, drawing parallels to recommended exercise frequencies.
  • While the cardiovascular advantages are significant, saunas have also been linked to other health benefits, like reducing the incidence of colds and alleviating chronic tension headaches.

Conclusion

The conversation with Earric Lee underscores the importance of saunas in the modern wellness landscape. Beyond mere relaxation, saunas may hold the key to enhanced cardiovascular health and overall well-being. To read the full research study, click here.

About Earric Lee

Dr. Earric Lee Image with a Harvia Sauna

Earric Lee holds a Master's Degree in Biology of Physical Activity from the University of Jyväskylä and is currently involved in several other research projects within the faculty. Eric led this study which was published in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology.

"I started using the sauna two decades ago when I was still a competitive athlete to aid recovery, and for muscle relaxation. Back then, I had no idea that the sauna originates from Finland. I did not have regular access to a sauna once I ended my athletic career, but I would use it whenever I had the opportunity. When I came to Finland in 2015, I realized that they were everywhere, so I started using them more frequently."

- Dr. Earric Lee

"Cardiorespiratory fitness is often a major determinant for the average person who wants to improve their overall health and quality of life. CRF is commonly quantified by the measure of maximal oxygen uptake (VO2MAX), and is a representation of the maximum aggregated capacity of 1) the pulmonary system for oxygen uptake, 2) the cardiovascular system for the transportation of oxygen, and 3) the muscular system to utilize the oxygen, in sequence [6]. However, the maintenance of optimal cardiovascular system function also involves other key indices such as blood pressure and lipids, which are CVD risk factors as well."

- Dr Earric Lee

Other References:

[1] Ernst, E. (1989). Sauna - a hobby or for health?. Journal of the Royal Society of Medicine, 82(11), 639-639.

[2] World Health Organization (2020). Physical activity: Fact sheet. Retrieved from https://www.who.int/news-room/fact-sheets/detail/physical-activity (5th May 2022)

[3] Fried L. P. (2016). Interventions for Human Frailty: Physical Activity as a Model. Cold Spring Harbor Perspectives in Medicine, 6(6), a025916.

[4] Warburton, D. E., Nicol, C. W., & Bredin, S. S. (2006). Health benefits of physical activity: the evidence. CMAJ : Canadian Medical Association Journal, 174(6), 801–809.

[5] National Center for Health Statistics (US) (2017). Health, United States, 2016: With Chartbook on Long-term Trends in Health. National Center for Health Statistics (US).

[6] Poole, D., Wilkerson, D., Jones, A., (2008). Validity of criteria for establishing maximal O2 uptake during ramp exercise tests. European Journal of Applied Physiology. 102:403-410. DOI 10.1007/s00421-007-0596-3

[7] Luttrell MJ and Halliwill JR (2015). Recovery from exercise: vulnerable state, window of opportunity, or crystal ball? Front. Physiol. 6:204. doi: 10.3389/fphys.2015.00204

Disclaimer: There is no financial relationship or otherwise between Harvia and any of the members of the study’s research team. The study, and the study’s main author Earric Lee, was not supported by Harvia or any sauna-related company in any manner. As such, there is no conflict of interest. Additionally, we at ZiahCare do not own, endorse, or claim rights to this content. All information presented is for informative purposes only.

Question for the reader:

How do you incorporate sauna sessions into your wellness routine, and have you noticed any cardiovascular or other health benefits from regular use? Share your experiences below!