WHY I JUST ORDERED A BARREL SAUNA
What Science Now Knows About the Sauna
For thousands of years, people across Finland, Scandinavia, Japan and indigenous North America have gathered in small, hot rooms and sweated together. It was ritual AND medicine. Modern science is discovering what these cultures have known for ages: sitting in intense heat does something profound to the human body… going far beyond relaxation.
Many studies, mostly from Finland, show sauna use as one of the most accessible whole-body health interventions available. Continue reading to learn what the evidence shows and the myriad of benefits from head to toe.
CARDIOVASCULAR
Your Heart Gets a Workout
When you step into a sauna, your body responds to the heat much as it would to moderate aerobic exercise. Heart rate climbs, blood vessels dilate, and circulation increases. Over time, this repeated "cardiovascular conditioning" appears to provide lasting preventative effects.
The most significant evidence comes from Finland's Kuopio Ischaemic Heart Disease (KIHD) Study which tracked the health of thousands of Finnish men for decades. It found that men who used a sauna 4 to 7 times per week had significantly lower rates of fatal cardiovascular events compared to those who used it only once a week.
(as you continue to read this post you may wonder why most of the studies specify men… so did I. This one took place in the mid-1980s, when eastern Finland had one of the highest rates of heart disease in men globally. Women were added to follow-up studies, and more recent research has confirmed similar cardiovascular benefits across genders. But the gap is real, and fortunately science is starting to catch up.)
47%
Reduced likelihood of developing hypertension among those taking 4-7 saunas per week compared to once weekly, in a study of over 1,600 men followed for more than 2 decades.
The blood pressure benefits alone are mind-boggling. One study found that sauna sessions reduced blood pressure for at least two hours afterward. The Mayo Clinic has published a review confirming that regular sauna therapy is associated with reduced hypertension and cardiovascular disease across multiple independent studies.
The most likely reason for this: heat causes blood vessels to dilate, which trains the lining of your vessels to become more flexible and responsive… sort of like vascular yoga.
BRAIN HEALTH
The Sauna and Dementia
Scientists at the University of Eastern Finland found a relationship between sauna use and a lower risk of dementia and Alzheimer's. The study followed more than 2,000 healthy Finnish men between the ages of 42–60 for over 20 years (again with the mens, I know).
66%
Lower risk of any dementia diagnosis when using a sauna 4–7 times per week, compared to those who used it just once a week. The risk of Alzheimer's specifically was 65% lower.
The results held, even when considering age, blood pressure, alcohol-use, smoking, cholesterol, and chronic illness, meaning it wasn't simply a substitute for other healthy behaviors.
A second, broader study found that the length of the session matters. Staying in the heat for 5–14 minutes per session (vs under 5 minutes) was linked to a reduced risk of Alzheimer's. The temperature range was 176–210°F.
Researchers attribute these statistics to improved blood flow to the brain, reduced inflammation, and the release of heat shock proteins, which help the body repair damaged proteins at the cellular level, including the kind linked to diseases like Alzheimer's.
Note: these were observational studies, and more research is needed to confirm causation.
LYMPHATIC SYSTEM
The Lymphatic System
The lymphatic system is a network of vessels, nodes, and ducts that removes waste, fights infection, and regulates fluid balance. Unlike the circulatory system, lymph has no pump of its own. It depends on muscle movement, breathing and manual stimulation (such as dry brushing or massage) to keep moving.
When body temperature rises, blood vessels dilate, increasing circulation. This enhanced flow creates pressure that moves lymphatic fluid through the vessels, while sweating helps the body excrete toxins. Research has detected heavy metals including lead, mercury, and arsenic in sweat, as well as environmental pollutants like BPA and phthalates.
Once again, the results are better for those using saunas 4-7 times per week. There was also a lower risk of respiratory illness as a healthy lymphatic system is connected to immune response.
MENTAL HEALTH + MOOD
A Tool for Depression
Depression affects more than 280 million people worldwide, and some can’t achieve full improvement with standard treatments.
Researchers at the University of California San Francisco (UCSF) Osher Center for Integrative Health are pioneers of this work. In a 2024 trial published in the International Journal of Hyperthermia, 16 adults with depression received eight weekly sessions combining infrared sauna with cognitive behavioral therapy. The results: 11 out of the 12 participants were no longer considered clinically depressed.
50%
Reduction in depression symptoms following heat therapy, in some cases after just a single session.
Heat exposure activates serotonin-producing neurons in the brain, stabilizing mood and reducing anxiety. It also triggers endorphins, similar to a runner's high. After heat exposure, the nervous system rebounds: heart rate drops, cortisol falls, and muscles relax.
It also helps with sleep, which is closely connected with mental health. As body temperature rises during a session and then drops afterward, it tells the brain that it’s time to sleep, improving both the time it takes to fall asleep and overall sleep quality.
MUSCLE, JOINT + PAIN RELIEF
Chronic pain, sore muscles & arthritic joints
For those dealing with musculoskeletal pain, the evidence for sauna as therapy is real. Heat increases blood flow to muscles, reduces spasm, and has been shown to improve chronic back pain.
Research shows that sauna use eases muscle stiffness and supports training capacity. For people with rheumatoid arthritis, studies have shown that pain eased, stiffness decreased, and mobility improved after sessions. Heat calms inflammation, lowers stress, and promotes relaxation which reduces pain, instead of simply masking it.
Heat shock proteins, produced during sauna exposure, play a supporting role too by repairing damaged cellular proteins and reducing inflammation that contributes to chronic pain.
RESPIRATORY HEALTH
Breathe easier
From asthma to lung disease… the benefits of regular sauna use extend into the respiratory realm. Research shows that sauna use can help lung function in people with asthma and COPD. Wet saunas in particular hydrate the respiratory tract, improving the ability to move mucus which is useful for anyone dealing with congestion.
The same Finnish studies that reported cardiovascular and dementia benefits also found a significantly lower risk of respiratory illness among frequent users. The Mayo Clinic confirmed these findings, listing improved respiratory conditions among the benefits of regular a sauna practice.
SAFETY
Sauna use is safe for most people when approached sensibly, but a few guidelines are worth keeping in mind:
- Consult your doctor first if you have cardiovascular disease, unstable blood pressure, kidney disease, or are pregnant.
- Limit sessions to 5–20 minutes, especially when starting out. Most research used sessions in this range.
- Hydrate well before and after — sauna-induced sweating can cause significant fluid loss.
- Avoid alcohol before or during sauna use, which raises cardiovascular risk substantially.
- If combining with cold plunge or cold shower, transition gradually… the cardiovascular response can be intense.
- People with skin conditions or heat sensitivity should check with their doctors before regular use.
