Sauna and Heart Health: What the Finnish Studies Found

Quick answerIn a 20-year study of 2,315 Finnish men, those who used the sauna four to seven times a week had a substantially lower risk of fatal heart events than those who went once a week, and longer sessions were linked with lower risk too. It is observational research, so it cannot prove the sauna caused the difference, but it is one of the most-cited studies in the field.

The study

The research comes from the Kuopio Ischaemic Heart Disease Risk Factor Study, which has followed men from eastern Finland since the 1980s. In 2015, researchers published the sauna findings in JAMA Internal Medicine. They grouped the men by how often they used the sauna (once, two to three, or four to seven times a week) and by how long each session lasted.

What they found

Compared with once-a-week users, men who used the sauna more often had a lower risk of sudden cardiac death, fatal heart disease and death from any cause, and the pattern got stronger with frequency. Session length mattered as well: men whose sessions lasted more than 19 minutes had lower risk than those who stayed in for under 11 minutes.

Why it might help

Researchers suggest a few reasons. Heat widens blood vessels and raises heart rate in a way that resembles moderate exercise. Over time, regular heat exposure may help blood vessels stay flexible and help blood pressure settle. Follow-up research on the same men found frequent sauna users were less likely to develop high blood pressure.

The fine print

• The study included men only, mostly from one region of Finland.
• Sauna is deeply woven into Finnish life, and frequent users may differ in other healthy ways.
• Finnish saunas are typically 80–100°C with low humidity. Infrared saunas run cooler and have been studied far less.

What it means for your routine

The takeaway is not to push for longer or hotter sessions. It is that the people in this study made sauna a regular, comfortable part of their week. Find a temperature and session length that feels good, drink water, cool down properly, and build the habit.

If the heat on your head is what usually sends you out early, a thick wool sauna hat keeps the hottest air off your head so the rest of the session stays comfortable. Here's how it works.

General information only, not medical advice. If you have a heart condition, high or low blood pressure, or are pregnant, speak with your doctor before using a sauna.