Physical activity is perhaps the most important lifestyle factor in the promotion of heart health because of the beneficial stress it puts on the heart. Sauna bathing puts similar stress on the heart by increasing cardiac output in an effort to cool the body, making it a good choice for people unable to meet exercise guidelines; however, people who combine activities may experience unique benefits. Findings from a report released this month demonstrate the robust beneficial effects of combined physical activity and sauna bathing on cardiovascular fitness and metabolic health.

Both sauna use and exercise increase pulse and blood pressure, activating a negative feedback loop that lowers blood pressure after the activity is over and for an extended period afterward. Adaptations to the metabolic and mechanical stress of exercise include an increase in heart size and mitochondrial density associated with better cardiovascular output, increased elasticity of blood vessels, and a reduction in white blood cells and inflammation. Previous research shows that sauna bathing provides some of the same benefits; however, because sauna use has just recently moved into the mainstream of clinical research, less is known about its mechanisms of action and effects when combined with exercise.

The authors recruited 47 participants (average age, 49 years) who did not exercise regularly and were at high risk of cardiovascular disease and randomly assigned them to complete eight weeks of exercise training with or without sauna or no exercise training at all. Participants in the exercise groups completed three days of exercise per week that included a 10-minute warm-up, 20 minutes of weight training, and 30 minutes of aerobic exercise. Participants in the sauna group followed their exercise training with 15 minutes of sauna bathing at 150 degrees Fahrenheit. The temperature of the sauna was increased by 40 degrees Fahrenheit every two weeks as participants acclimated to the heat stress. The participants completed a cardiorespiratory fitness test at the beginning and end of the study during which they peddled an exercise bike at increasing resistance levels to increase heart rate. They also provided blood samples and had their body composition measured.

Eight weeks of exercise training increased maximal heart rate (measured by VO2max or maximal oxygen intake) and reduced fat mass; however, participants did not experience a significant reduction in blood pressure, arterial stiffness, or total cholesterol compared to the participants who did not exercise. Participants who completed sauna bathing in addition to exercise experienced an even greater increase in maximum heart rate and lower systolic blood pressure (reduction of 8 mmHg in systolic blood pressure and 3 mmHg in diastolic blood pressure) and total cholesterol (12 milligrams per deciliter reduction). Participants in the exercise without sauna group experienced no reduction in systolic blood pressure and only a minor reduction in diastolic blood pressure (0.6 mmHG).

The findings of this study demonstrate the unique benefits of sauna use in addition to exercise. Future studies with a greater number of participants and more diverse sauna bathing conditions would be valuable additions to this research.

• Link to the full publication.

• Watch this clip with Dr. Jari Laukkanen, coauthor of this research, discussing the dramatic effects of sauna use on blood pressure.

• Learn more about sauna use in our overview article on the topic.