November 15, 2026, 4:40 pm | Read time: 5 minutes
Long-term studies from Finland show that regular Finnish sauna use is associated with a significant reduction in the risk of sudden cardiac death, fatal cardiovascular diseases, and overall mortality. Especially for older people, sauna bathing is an effective tool for health promotion. What beginners should keep in mind can be read at FITBOOK.
What Happens in the Body During Sauna Bathing
During sauna bathing, the body responds to the high ambient temperature by trying to shed excess heat. The blood vessels in the skin dilate, the skin becomes more perfused, and the body begins to sweat. At the same time, the heart rate increases. In a recent study with 50 participants on the effects of temperature and humidity during Finnish sauna sessions, it was found that the heart rate increased by an average of 41.6 beats per minute during a ten-minute sauna session. The core body temperature rose by an average of 0.4 degrees Celsius.1
Also interesting: 14 Days of Daily Sauna – What It Did to My Body
How Long a Sauna Session Should Last
Ten to 15 minutes are considered scientifically and practically as the optimal guideline per sauna session. The International Sauna Academy cites 15 minutes as the upper guideline, but the quarter-hour should not be seen as a performance goal. A sauna session is not an endurance contest!2 The hourglass is not decisive: If you feel uncomfortable, dizzy, or overly strained beforehand, you should leave the sauna.
How Many Sauna Sessions Are Beneficial
There is no fixed number of sauna sessions that is ideal for every person or every type of sauna. There is also no need for all sauna sessions to be exactly the same length. Research typically uses two to four rounds per session. For example, the Finnish study from 2026 used a protocol of four ten-minute sauna sessions (with 30-minute rest breaks in between).
Aside from that, regular sauna use brings long-term health benefits!
Whether a Steam Infusion Is Necessary
In Finnish sauna bathing, air temperature is the dominant driver for the increase in heart rate and core body temperature. Higher humidity (by pouring water on the hot stones) prevents sweat from evaporating effectively on the skin, impairing the body’s primary cooling mechanism. For experienced sauna users, the steam infusion is a means to intensify the heat stimulus.
Beginners should preferably conduct sauna sessions without a steam infusion (or with very low humidity). This keeps the thermal load manageable and does not overstrain the cardiovascular system. Even the pure heat of dry air leads to a significant increase in heart rate and peripheral vasodilation. From a scientific perspective, a steam infusion is not strictly necessary to trigger the primary cardiovascular adaptation responses.
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The Right Temperature
Most long-term health data on sauna use comes from studies on the traditional Finnish sauna–typically at 80 degrees Celsius. In everyday practice, Finnish saunas are usually operated in a range of 70 to 100 degrees Celsius.
However, research does not identify a specific temperature at which sauna bathing suddenly becomes “healthy.”
Study on the Acute Effects of a Sauna Session
A sauna session (three times ten minutes at 80 degrees) produces a physiological cardiovascular load comparable to moderate endurance activity, according to a 2025 study. Acute result: a slight reduction in blood pressure.3
These Are the Long-Term Benefits
Regular sauna use is associated with a significant reduction in the risk of sudden cardiac death, fatal cardiovascular diseases, and overall mortality.
Long-term sauna use lowers blood levels of the inflammatory marker C-reactive protein (CRP), counteracting chronic systemic inflammatory processes.
Repeated sauna bathing permanently improves endothelial and vascular function, reduces vascular stiffness, and contributes to a sustainable reduction in blood pressure.
Additionally, regular passive heat therapy promotes increased insulin sensitivity and supports overall cardiometabolic health.
How Do the Different Types of Saunas Differ?
The Mistake Many People Make After the Sauna
The Importance of Cooling Down and Recovery
Important: The cooling down and recovery phase after sweating is not merely an “add-on” but is essential for physiological reasons. During sauna bathing, the body’s thermal and cardiovascular safety reserve is reduced due to heat exposure, increased core temperature, and heart rate. Only through the subsequent cooling down and recovery phase is this reserve fully restored. Additionally, heart rate and core temperature return to their baseline levels.
Cold water also provides a significant cold stimulus and causes the previously dilated blood vessels in the skin to constrict again. However, you don’t necessarily have to jump into an ice-cold plunge pool. A cold water bath lowers heart rate and core temperature more effectively before the next session than just air cooling. If cooling is insufficient, you start the next sauna session with an already increased heat load and reduced heat tolerance.
Fluid Loss – How Much You Should Drink
The extent of fluid loss depends on factors such as temperature, humidity, duration, and individual sweating behavior. It is more practical to compensate for the actual fluid loss: If you want to know exactly, you can weigh yourself before and after sauna bathing. Participants in the aforementioned 2025 study lost an average of 0.66 kilograms of body weight through sweating during a sauna session of three times ten minutes at 80 degrees. In the 2026 study, the sweat loss per ten-minute session averaged 0.10 kilograms.
For a normal sauna visit, water is usually sufficient as a beverage. It is especially important not to enter the sauna already thirsty or dehydrated.