Saratoga Springs has been called the Spa City for a long time. People came for the waters and stayed for the ritual. A Finnish sauna is the same idea in a different form: heat, rest, a little cold, and time with people you like.
If you have never tried one, here is what to expect and why so many people make it a habit. This article is not medical advice. If you have a heart condition, are pregnant, or take blood pressure medication, talk to your doctor before your first session.
What a sauna actually feels like
A traditional Finnish sauna is a wood-lined room heated by a stove, usually somewhere between 70°C and 100°C (about 160°F to 210°F). It sounds extreme. In practice the air is dry, the wood is warm, and the first few minutes feel like stepping into the best part of a summer afternoon.
Then your body gets to work. Your heart beats faster and your skin flushes as blood moves toward it to shed heat. In one lab study of 19 healthy adults, the load on the heart during a sauna session was about the same as moderate exercise, the kind you would feel on a brisk walk or an easy bike ride.1
After you step out, things settle. In a study of 102 adults, blood pressure was lower right after the session than before it, and the top number was still lower half an hour later.2 That drop is temporary, but it is part of why the minutes after a sauna feel so loose and calm.
Why people keep coming back
Ask regulars why they go, and the answers are rarely about a single health number.
- It helps them unwind. In a survey of 482 regular sauna users from around the world, relaxation and stress relief were among the top reasons people gave for going.3 In a small study of 45 people at a Japanese charcoal kiln sauna, every mood and anxiety score measured improved after a session.4 It was a small study with no comparison group, so take it as a reason to try it rather than a guarantee.
- They sleep better, or feel like they do. In that same global survey, 83.5% of regular users said they noticed sleep benefits after a sauna.3 That is what people report, not something measured in a sleep lab, but it is a lot of people saying the same thing.
- It is social. Across three studies of nearly 1,900 sauna-goers in the UK, researchers linked the ritual and the shared feeling of a sauna session with better emotional wellbeing over time.5 In Finland a sauna has long been where friends talk and families gather. The heat slows everyone down enough to have a real conversation.
- Their bodies respond to the heat. Sauna heat triggers a short burst of hormones. In small lab studies, levels of beta-endorphin, one of the body's own feel-good chemicals, went up during a sauna, and cortisol went down in some sessions.6, 7 Researchers are still working out what that means over the long run.
What the long-term research says
The most famous sauna research comes from eastern Finland, where scientists followed more than 2,000 middle-aged men for about 20 years. Men who used the sauna 4 to 7 times a week had lower rates of fatal heart disease than men who went once a week.8 A later analysis from the same region, which included women, linked frequent sauna use with lower rates of stroke.9
Two things matter about those findings. First, they show an association, not cause and effect: people who sauna often may also be healthier in other ways. Second, most of the people studied were Finnish men, so the results may not apply to everyone. Researchers are still studying why regular sauna use is linked to better heart health.10
You do not need a study to enjoy a sauna, but it is nice to know that a habit this pleasant has a long track record behind it.
Who should check with a doctor first
Most healthy adults tolerate a sauna well.11 Talk to your doctor before your first session if you have:
- Unstable angina, a recent heart attack, or severe aortic stenosis.11
- Any other heart condition, or blood pressure that isn't well controlled.12
- A seizure disorder.13
- A pregnancy. Ask your OB or midwife first.
The short version
A sauna is warm, quiet and social. Your heart works about as hard as on a brisk walk, your blood pressure dips afterward, and most regulars say they leave calmer and sleep better. The long-term research from Finland is encouraging, even if it can't show cause and effect. The best way to find out what it does for you is to try one.