Every now and then something that feels great turns out to be great for your health. This time it’s the modern sauna—a room that radiates dry heat.

Saunas have had a healthy reputation for a long time, to be sure, but scientific evidence has been scant—mostly small, short-term studies. Now there’s compelling new research that has tracked the long-term health of thousands of sauna-taking men and women over a period of more than 20 years—and found wide-ranging benefits for the heart, the respiratory system and the brain.

Not surprisingly, the new studies are coming from Finland, where the sauna has been a part of home life for millennia. But even in the US, there’s a sauna at many gyms, and new kinds of home saunas are increasingly affordable and popular—imagine taking a relaxing dry sauna any time you want! (For buying advice, see the Bottom Line article, “The Best Home Sauna for Any Budget.”) Here’s a look at the scientifically proven benefits of dry sauna—and how to get them for yourself…

FOUR WAYS SAUNAS MAKE YOU HEALTHIER

Saunas are such a part of Finland’s culture that nearly everyone uses one. So rather than comparing people who use them frequently to those who never use them, researchers compared frequent users with infrequent ones. They then took steps to control statistically for the fact that people who use saunas frequently might live healthier lives in other ways as well, such as exercising more or smoking less. Among the health benefits of taking saunas often…

A healthier heart. A 20-year study published in JAMA Internal Medicine found that people who took saunas four to seven times a week were 50% less likely to develop cardiovascular disease than those who took saunas only once a week or less. They were also 63% less likely to die from a sudden cardiac event. What’s more, a second study, published in American Journal of Hypertension, found that the risk of developing high blood pressure was 46% lower among men who took saunas four to seven times each week versus once a week or less. Regular sauna use increases blood flow and heart rate much in the way that cardiovascular exercise does—and improves the function of the inside layer of blood vessels in ways that are beneficial for blood pressure.

Protection from dementia. Research published in Age and Ageing found that middle-aged men who took 15-minute saunas four to seven times per week were 66% less likely to develop dementia than were men who took one sauna per week or less. One reason may be the cardiovascular benefits that improve blood flow to the brain.

Less respiratory disease. A study published in European Journal of Epidemiology found that middle-aged men who took at least four saunas per week were 41% less likely to develop certain serious respiratory conditions including chronic obstructive pulmonary disease (COPD)…asthma…and pneumonia. One hypothesis is that these benefits stem from the sauna’s ability to reduce congestion in the lungs and airways.

A longer life. A healthier heart, brain and lungs may add up preventing premature death. That study published in JAMA Internal Medicine also found that middle-aged men who took saunas four to seven times each week were 40% less likely to die from any cause during the 20-plus-year study than were men who used the sauna only once a week or less.

YOUR SAUNA STRATEGY

The research conducted to date strongly suggests that taking the occasional sauna when you visit a hotel or spa is not enough to derive significant health benefits. The secret to saunas is to use them often—ideally every other day to every day. Having a sauna at home could be the most practical way to do that (see below).

How long you spend in the sauna and how hot the sauna is matters, too. Odds of experiencing sudden cardiac death were 52% lower for men who typically spent more than 19 minutes in the sauna versus 11 minutes, studies show. Various studies confirm that the recommended sauna temperature is about 175˚F at head level.

Spending that much time in a hot sauna is likely to make your heart rate accelerate, and it might no longer feel completely comfortable—but maybe that’s the point. With cardiovascular exercise, our bodies tend to derive the greatest benefits when we push ourselves a little bit beyond the point where the exercise is easy, so it shouldn’t be a big surprise that the same might be true with saunas. Warning: People who have high or low blood pressure, or other cardiovascular problems, should speak with their doctors before taking saunas—and in fact, that’s a good idea for everyone just to make sure that the heat won’t be risky for you.

So far, almost all of the research on health benefits has been done on the traditional “dry” sauna—often called a “Finnish” sauna in the US. This type of sauna features very little steam and humidity levels of just 10% to 20%. Popular “infrared” saunas, which also are dry but work on a different principle to heat the body, have been shown to reduce blood pressure and have other short-term health benefits, but there’s no long-term data. Nor do we know much about the health effects of steam rooms, although they, too, create a passive cardiovascular workout.

SAUNA BEST PRACTICES

Important advice for safe, effective use of a sauna…

  • The best temperature is around 175˚F, although you’ll get benefits over 160˚F. Avoid going 195˚F —that’s unsafe for everyone.
  • A duration of 20 to 30 minutes is ideal.
  • When you leave the sauna, let yourself cool down for a few minutes by just sitting in a normal-temperature room—and drink two to four eight-ounce glasses of water.
  • Saunas are places where people sit or stand and perspire. So they should be cleaned regularly.
  • Don’t drink alcohol an hour or two before a sauna—or during. The combination of heat and alcohol can make blood pressure drop too low.
  • Don’t let your sauna buddies compete to see how hot you can make it. A sauna should be a place to relax—whether by yourself or with family or friends—after a busy, stressful day or after exercising.