Short answer: Saunas are hot rooms used for short heat sessions, traditionally 80 to 100°C in a Finnish sauna. Long-term Finnish studies link frequent use with lower risk of fatal heart events, but those studies are observational. A 2018 systematic review called the benefits promising but the evidence limited. The key safety rules are to skip alcohol and avoid bathing alone.
This refresh drops the old post's detox and skin claims and sticks to what research reviews say.
What types of sauna are there?
From Hussain and Cohen's 2018 systematic review:
| Type | Typical setup |
|---|---|
| Traditional Finnish | 80 to 100°C, dry air (10 to 20% humidity) with bursts of steam from water thrown on hot rocks; sessions of 5 to 20 minutes |
| Infrared | Infrared emitters, no added humidity, usually 45 to 60°C, similar session lengths |
Both styles can include cooling-off periods and rehydration between rounds.
Where did saunas come from?
A 2018 review in Mayo Clinic Proceedings (Laukkanen and colleagues) describes sauna bathing as a tradition in Finland for thousands of years, used mainly for pleasure and relaxation, and now spreading to many other countries.
What does the research say about sauna benefits?
- Heart and mortality (observational): Laukkanen and colleagues (JAMA Internal Medicine, 2015) followed 2,315 middle-aged Finnish men for a median 20.7 years. Compared with one session a week, 4 to 7 sessions a week was associated with lower risk of sudden cardiac death, fatal coronary heart disease, fatal cardiovascular disease, and death from any cause. Longer sessions (over 19 minutes) were also linked with lower sudden cardiac death risk.
- Overall evidence: Hussain and Cohen reviewed 40 studies with 3,855 participants. Only 13 were randomized trials and most were small. They concluded regular dry sauna bathing has potential health benefits but more high-quality data is needed.
Observational data can't prove sauna use caused those outcomes. People who sauna often may differ in other ways.
Is sauna use safe?
For most healthy people in the reviewed studies, side effects were mild to moderate: heat discomfort, light-headedness, and airway irritation. The 2018 review also lists rarer serious events reported in the wider medical literature, including burns, fainting and falls, heat stroke, and heart problems, especially in people with unstable coronary artery disease.
The strongest practical warning: in Swedish and Finnish studies of sauna deaths, half or more involved alcohol, and bathing alone was a common risk factor. One small study also found reversible effects on sperm production in men.
Practical rules:
- No alcohol before or during a sauna.
- Don't sauna alone.
- Get out if you feel dizzy or light-headed.
- Rehydrate and take cooling breaks.
- Talk to a doctor first if you have a heart condition.
How do athletes use saunas?
Most use them for relaxation after training, which is where the tradition started. If you also use cold water, our cold plunge research guide covers what that evidence shows, including the cold shock risk. For the bigger recovery picture of food and sleep, see our 3 week diet plan for lifters.
FAQ
How hot is a sauna?
Traditional Finnish saunas generally run 80 to 100°C with dry air and short sessions of 5 to 20 minutes. Infrared saunas usually run cooler, around 45 to 60°C.
Is sauna use good for your heart?
A Finnish study of 2,315 men followed for about 20 years linked more frequent sauna use with lower risk of fatal cardiovascular events. It was observational, so it shows an association, not proof of cause.
Is it safe to drink alcohol in a sauna?
No. A 2018 systematic review notes that in Swedish and Finnish studies of sauna deaths, half or more involved alcohol, and bathing alone was a common risk factor.
Does a sauna detox your body?
None of the research reviews cited here support detox claims, so this guide doesn't make them.
Next rep
If you sauna after training, bring a partner and a water bottle, and keep the first sessions short.
Sources
- Hussain and Cohen, 2018: Clinical effects of regular dry sauna bathing, a systematic review
- Laukkanen et al., 2015: Sauna bathing and fatal cardiovascular and all-cause mortality events (JAMA Internal Medicine)
- Laukkanen et al., 2018: Cardiovascular and other health benefits of sauna bathing (Mayo Clinic Proceedings)