Sauna & heart health: what the Finnish studies show
Regular sauna use is more than relaxation: large long-term studies from Finland link it to a healthier heart and a higher life expectancy. What lies behind it.
What heat does to your cardiovascular system
In the sauna, skin temperature rises noticeably within a few minutes and core body temperature by about one degree. The body responds by dilating blood vessels and directing more blood to the surface. Heart rate climbs to 100 to 130 beats per minute — a range comparable to moderate exercise.
At the same time, peripheral vascular resistance drops and blood pressure falls during and after the sauna session. This combination resembles what light endurance training produces. The difference: your muscles aren't doing any work. Sauna therefore doesn't replace exercise, but it does place a related stimulus on the vascular system.
The Finnish long-term data
Laukkanen and colleagues analysed data from 2,315 Finnish men in 2015, followed over an average of twenty years. Those who used the sauna four to seven times a week had a markedly lower risk of fatal cardiovascular events and all-cause mortality compared with those who used it once a week.
The association was dose-dependent: two to three times a week fell in between. Duration also played a role — sauna sessions of more than nineteen minutes were associated with lower risk than shorter ones. The authors adjusted for age, smoking, blood pressure, cholesterol and physical activity.
What this data shows — and what it doesn't
This is an observational study. It can show that two things occur together, but it cannot prove that sauna is the cause. Someone who uses the sauna four times a week may simply have more time, less stress, or be healthier to begin with — factors that can never be fully adjusted away.
Laukkanen and colleagues compiled the further evidence in 2018: short-term studies do show improvements in blood pressure, vascular stiffness and vascular function. This makes a causal contribution plausible. It does not prove it.
How often, how hot, how long
In the Finnish studies, the typical temperature was 80 to 90 degrees in a dry sauna, with sessions of 10 to 20 minutes each and two to three rounds. Those who want to see the greatest association aim for four times a week — but even twice already showed an effect.
More important than pushing limits is cooling down and drinking enough. A sauna session costs roughly half to a full litre of fluid depending on its length. The cold rinse afterwards is a matter of habit; for your circulation, gradual cooling is the gentler option, especially for beginners.
When sauna isn't suitable
Sauna should be avoided in cases of: unstable angina pectoris, a heart attack in the past few weeks, severe aortic valve stenosis, and acute infections with fever. With treated high blood pressure, sauna is generally possible but should be discussed with your doctor.
Two rules apply to everyone: no alcohol beforehand, as it puts additional strain on the cardiovascular system and dulls your awareness of warning signs — and don't use the sauna alone if you're unsure. During pregnancy, sauna is usually safe with an uncomplicated course, but not when complications are present. This content does not replace medical advice.
How the YUTHI app helps you
You log your sauna sessions with their duration, and the app places them alongside your resting heart rate, blood pressure and sleep. For many people, a pattern emerges that's more convincing in their individual case than any study: nights after an evening sauna session tend to be more restful.
Vito and Vita also keep an eye on the downside. If you sleep badly after a sauna or feel exhausted the next day, you either went too hot or too late — and you'll get a specific note on that rather than a blanket recommendation.
That was the snapshot. The app turns it into daily support.
Measure every day instead of calculating once: Vito or Vita puts your numbers in context, builds you a weekly plan and speaks up when something stands out.
Launching at the end of 2026 — iPhone first, Android to follow. Let me know when it’s out ↓
Sources
- Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Intern Med. 2015;175(4):542-548.
- Laukkanen JA, Laukkanen T, Kunutsor SK. Cardiovascular and Other Health Benefits of Sauna Bathing: A Review of the Evidence. Mayo Clin Proc. 2018;93(8):1111-1121.
- Laukkanen T, Kunutsor SK, Zaccardi F, et al. Acute effects of sauna bathing on cardiovascular function. J Hum Hypertens. 2018;32(2):129-138.
- Kunutsor SK, Khan H, Zaccardi F, Laukkanen T, Willeit P, Laukkanen JA. Sauna bathing reduces the risk of stroke in Finnish men and women: A prospective cohort study. Neurology. 2018;90(22):e1937-e1944.