The Science Behind Sauna & Exercise

There is an overwhelming amount of evidence showing that combining sauna baths with regular exercise creates the highest level of physical conditioning possible. Fitness is an independent predictor of overall mortality and cardiovascular diseases. To understand the significance of combining sauna baths and regular exercise for enhancing fitness, it is necessary to evaluate previous studies that were conducted to establish a scientific basis for the current study.

The Science of Sauna Bathing and Exercise

Hormesis is a biological response to stress, which causes the body to produce heat shock proteins. Both exercise and sauna baths create stress in the body, therefore both can cause an increase in production of these proteins. The mechanism of how exercise causes heat shock proteins is based on increased heart rate and metabolic demand caused by contracting muscles. Sauna baths, however, increase the heart rate to 150 beats per minute without causing contraction in muscles. Therefore, sauna baths create stress in the body differently than traditional exercise.

What the Evidence Says

In the past few years, the Mayo Clinic reviewed multiple studies about the relationship of sauna baths and exercise. The Mayo Clinic found many of the studies demonstrated the following:

• 47% reduced risk of developing high blood pressure.
• Reduced risk of having heart attacks.
• Reduced risk of strokes by 62%.
• Reduced risk of dementia by 66%.
• Greater benefit when using sauna baths with exercise compared to exercise alone.

These findings have created great interest; however, much of the data was collected from observational studies. Observational studies examine population trends and are unable to account for external factors such as socioeconomic status and overall health-conscious behavior that may contribute to the results of the study.

The Breakthrough Study

Therefore, the first major gap in the data was addressed with a randomized controlled study that investigated the effect of combining exercise and sauna baths on cardiovascular health.

Study Details

• Participants: 48 individuals (ages 30-64) from Finland who led a sedentary lifestyle and had at least one risk factor for heart disease (e.g., high cholesterol).
• Duration: 8 weeks
• Protocol:
  • Exercise Group: 3 times/week for 60 minutes (10 minute warm-up, 20 minute resistance training, 30 minute aerobic exercise).
  • Exercise + Sauna Group: Same protocol as above, followed by a 15 minute sauna session (65°C at week 1, increasing by 5°C each two weeks).

Results

Fitness Levels

At the beginning of the study, the sauna bath group was less fit than the exercise only group. By the end of the study, the sauna bath group had reached the same fitness level as the exercise only group. It is uncertain if the sauna baths contributed to reaching the same fitness level as the exercise only group.

Blood Pressure

Compared to the exercise only group, the sauna bath group showed a significant decrease in blood pressure. The results indicate additional cardiovascular benefits associated with sauna baths.

Cholesterol Levels

In comparison to the exercise only group, total cholesterol levels also decreased significantly in the sauna bath group. The results further support the positive effect of sauna baths on heart health.

Conclusion

Although the study has limitations due to the small sample size and the short duration, the results suggest that sauna baths may augment the cardiovascular benefits of exercise. Specifically, sauna baths appear to reduce blood pressure and cholesterol levels in addition to those produced by exercise. For a deeper look at this topic, see the science behind sauna and exercise.

Research Sources

• pubmed.ncbi.nlm.nih.gov
• pmc.ncbi.nlm.nih.gov
• mayoclinicproceedings.org
• onlinelibrary.wiley.com