Sauna Benefits: What the Research Actually Says

The short answer: regular sauna use is linked with better heart health and a longer life in some large, long running studies, and it reliably makes most people feel relaxed. The catch is that most of that research is observational and comes from middle aged Finnish men, so it shows an association, not proof that the sauna caused the benefit.

That's still a lot more than most wellness habits can claim. Here's what the studies found, who they looked at, and where the gaps are.

Where most of the research comes from

Nearly every headline about sauna benefits traces back to one project in Finland, the Kuopio Ischaemic Heart Disease Risk Factor Study. Researchers followed 2,315 men, aged 42 to 60 when they joined, for about 20 years. They asked how often each man used a sauna and then tracked what happened to their health.

Finland is a good place to ask that question because almost everyone there saunas. That's also its weakness, which we'll come back to.

Heart health

The best known paper from that group was published in JAMA Internal Medicine in 2015. Compared with men who used a sauna once a week, men who went 4 to 7 times a week had a much lower risk of sudden cardiac death, of dying from heart disease, and of dying from any cause during the follow up. Men who went 2 or 3 times a week sat in between. Longer sessions were also linked with lower risk of sudden cardiac death.

The pattern was dose dependent, meaning more sauna went with lower risk. That makes the result more interesting, but it still doesn't prove cause. Men who can sauna most days may also have more free time, less stress or healthier habits, and a study like this can only adjust for so much.

Brain health

The same group of men turned up again in a 2017 paper in Age and Ageing. Men who used a sauna 4 to 7 times a week had a lower risk of being diagnosed with dementia and Alzheimer's disease over the next two decades than men who went once a week. The 2 to 3 times a week group showed a smaller difference that wasn't statistically significant.

The authors suggested heart and blood vessel effects might explain part of it, and that the relaxation of sauna could play a role. They were clear that more research is needed.

What the bigger reviews say

Two reviews pull the wider research together.

A 2018 review in Mayo Clinic Proceedings, written by researchers from the Finnish studies, looked at trials and observational studies on traditional Finnish sauna. It described links with lower risk of high blood pressure, heart disease, lung conditions, and some mental health conditions. It also noted that the body's response to sauna heat, a faster heart rate and wider blood vessels, has some things in common with moderate exercise. The authors said sauna use has a good safety profile for most healthy adults, and called for well designed randomized trials to confirm cause and effect.

A 2018 systematic review from RMIT University in Melbourne looked at studies of regular dry sauna bathing, including both traditional and infrared saunas. It concluded that regular dry sauna bathing has potential health benefits, and that more study is needed to work out the best frequency and length of sessions.

What we don't know yet

This part matters, so here it is in plain terms.

• Women are missing. The big Finnish cohort studied only men. We can't say the same links hold for women, though there's no particular reason to think heat works very differently.
• Almost nobody skipped the sauna. Very few men in the study never used one, so the comparison is mostly once a week versus more often, not sauna versus no sauna.
• Finns grow up with it. These are lifelong habits. The results may not apply in the same way to someone who starts at 45 in Calgary.
• It's observational. People who sauna a lot may differ from people who don't in ways the researchers couldn't measure.

None of that means the benefits aren't real. It means the honest wording is "linked with", not "proven to".

The benefits you'll notice right away

Set the long term studies aside and there are things most people notice on their first visit. You warm up all the way through, which counts for a lot in a Calgary November. You sit still for fifteen minutes without your phone. And if you go with a friend, you have a proper conversation, which is harder to come by than it should be. We wrote more about that last part in how to find the best sauna in Calgary.

Adding a cold plunge between rounds is a different experience again. Our contrast therapy guide explains how a hot and cold round works.

How to sauna sensibly

• Start short. A few minutes on the lower bench is plenty for a first round. Get out when you've had enough, not when a timer says so.
• Drink water. You sweat more than you think. Bring a water bottle and use it between rounds.
• Skip the drinks before. Alcohol and sauna heat don't mix well.
• Ask your doctor first if you're pregnant, have a heart condition, low or high blood pressure, or take medication that affects your heart rate.
• Rest between rounds. Sitting quietly after the heat is part of it, not a break from it.

Trying it in Calgary

The Good Spot is a social cedar sauna with cold plunge tubs and a lounge in East Village, steps from the RiverWalk. An Express session is 45 minutes for $29, a Regular session is 1 hour 45 minutes for $37, and first timers can get a week of unlimited sessions for $59, all plus GST and card fees. Towels, robes and sandals are included. More on the space is on our sauna in Calgary page.

If the research is right that frequency is what counts, the best thing you can do is find a sauna you'll keep going back to.

This article is general information, not medical advice. Heat and cold are intense. If you're pregnant, have a heart condition, high or low blood pressure, or any other health concern, check with your doctor first.