Saunas - Healthy or Harmful?
Updated: Sep 21
Did you know that saunas have been around for 2000 years?! Finland is the most well-known country for sauna use; they have been home to Finland since as early as 1112. They’ve been touted for having benefits including flushing toxins, cleansing the skin, muscle recovery, and inducing deep sleep. I am lucky enough to have access to a sauna this week as we relax in the Adirondacks, and I’ve grown curious about the benefits. After doing a quick literature search, I have summarized findings for you below. These findings are from two systemic reviews of randomized-control trials (the gold standard of research!).
First, most studies on sauna use have a very low number of participants, making it hard to generalize study results. However, research does support some great benefits of sauna use! Saunas are beneficial for managing chronic pain and fatigue, cardiovascular disease, rheumatic diseases (such as fibromyalgia or rheumatoid arthritis), allergies, and chronic obstructive pulmonary disease (COPD). There are some people who should consider limiting or avoiding sauna use. One small study (with only 10 people) found that sperm production was disrupted with continuous sauna use. People with other health conditions (such as pregnancy, blood pressure problems, or who take certain medications) should be cautious about using a sauna. Never drink alcohol before or during sauna use. Take a friend with you for safety. When in doubt, talk to your provider before using a sauna.
What are the benefits of using a sauna?
Good news: in almost half of the studies reviewed, researchers included people with cardiovascular disease; all of these studies showed health benefits to participants. Exposure to heat increases cardiac output (the amount of blood the heart pumps per minute), reduces peripheral vascular resistance (the heart has an easier time getting blood where it needs to go), and decreases blood pressure – all great things for people with and without heart disease! Cardiac function markers (such as BNP) were improved as well. Other health markers were improved, including cortisol (your stress hormone), cholesterol, fasting blood glucose, and more. If you can believe it, using a sauna can also generate activity between free radicals and antioxidants – meaning the heat from the sauna can counteract the potential damage of free radicals (early aging, reduced immune response, etc.).
Cardiac Output Improves in Athletes:
Two small studies with elite athletes were given repeated exposure (30 minutes daily after exercise for 10 days) of sauna use. Researchers found that athletes increased their plasma volume (amount of blood) after 4 days of sauna use, though their levels went back to normal after about 7 days. Increased blood volume benefits the body greatly by increasing cardiac output, improving heart rate and blood pressure, and improving the body’s ability to regulate temperature.
Cholesterol levels improve:
Another study showed that cholesterol levels improved in healthy men after 4 weeks of 45 minutes sessions of sauna use. Cholesterol levels were also reduced in health women after just 2 weeks of 30 minutes sessions of sauna use.
Toxins are removed and health scores improve:
Another study with 20 women who used the sauna for 30 or 45 minute sessions over 2 weeks found improvements in heart rate, blood pressure, stress hormones, and blood volume.
An additional study found that people who were exposed to toxins in their workplace who completed 4 hour sauna sessions for 4-6 weeks had fewer sick days, slept longer, and better health scores. While most of us don’t have time to spend 4 hours in a sauna daily, this does support the claim that saunas help detoxify the body.
How often (and how long) should you use a sauna?
Most studies include time frames of 30 to 45 minutes of sauna use for at least two weeks to receive benefits.
What are the dangers of using a sauna?
As they say, there's no rose without a thorn! Though saunas promote positive changes in the body from mild stress due to heat, saunas can potentially over-heat the body and cause problems. Some people can react to heat by succumbing to heat stroke, have a heart attack, getting burns, and even dying. In Finland, the annual death rate from sauna use is 0.002% (or 2 in 100,000). Most of these deaths involved the use of alcohol and use of the sauna alone.
Other, less serious side effects of sauna use can include light-headedness, low blood pressure, heat discomfort or intolerance, airway irritation, and claustrophobia (fear of small spaces).
Men who are hoping to produce offspring should be mindful when using a sauna. In one study over a 3 month course of sauna use in 10 men, sperm production and quality was impaired. While infrequent, short-term use of a sauna is unlikely to effect sperm production, it’s worth knowing about if you are hoping to start a family. These men had normal sperm counts and quality after 6 months of avoiding a sauna.
Are there age restrictions for using a sauna?
While I find it hard to support sauna use in children due to the potential adverse affects, I must point out one study with 12 infants who had heart defects at birth. They were monitored in a sauna for 5 minutes daily for 4 weeks. 9 of them showed an improvement in their hearts that resulted in avoidance of surgical repair. Amazing!
Where can I find a sauna?
Saunas can be found in many gyms. You can easily find one by doing a quick search online for local saunas in the area. If you live in greater Cleveland, gyms such as LA Fitness, YMCA, Planet Fitness, and some hotels offer sauna use. If you don’t belong to one of the gyms that has a sauna, you can typically pay a fee (usually between $10 - $20) for a 24 hour guest pass with access to a sauna.
The Moral Of The Story
If you have certain illnesses (such as chronic pain or cardiovascular disease) or are looking to add a healthy habit to your current lifestyle, a sauna might be for you. If you are planning on starting a family or hoping to get pregnant, talk to your doctor or nurse practitioner before implementing routine sauna use. This is also recommended for people who take medications for some illnesses. It’s always a good idea to check with your provider before you start a new health regimen. Never drink alcohol before or during sauna use, and take a buddy with you when you go for safety! By following the above recommendations, most people can receive health benefits from regular sauna use.
Check out the below articles to see the research for yourself!
Hussain, J., & Cohen, M. (2018). Clinical Effects of Regular Dry Sauna Bathing: A Systematic Review. Evidence-Based Complementary & Alternative Medicine (ECAM), 2018, 1–30. https://doi.org/10.1155/2018/1857413
O, H. E., & Babione, J. (2017). Sauna as a Rehabilitative Component in Chronic Pain: A Systematic Review. Archives of Physical Medicine & Rehabilitation, 98(10), e107. https://doi.org/10.1016/j.apmr.2017.08.344