21 Feb It’s time to turn up the heat!
Vacations to warm destinations, pool parties, hot tubs, summer… even a heating pad or hot water bottle. Heat can bring us so much comfort and pleasure. But why? What is it about heat that makes us feel so good?
Research tells us that heat, especially heat therapies, offer tremendous benefits for the human body. Are you surprised? Doesn’t a few minutes in a sauna on a cold winter’s day make everything better?
What may be considered heat therapy?
Heat therapy includes hot tubs, dry, wet, and infrared saunas, and steam rooms. Many training facilities and gyms offer on-site saunas and/or steam rooms, and after learning about some of the benefits of partaking, you may want to make time for this mode of therapy too.
What does the research tell us?
Let’s consider one of the most significant studies looking at sauna bathing and fatal cardiovascular and all-cause mortality (death from any cause) events. There were 3 groups of participants based on frequency and duration of sauna bathing, 1, 2-3, and 4-7 times per week (frequency) and <11, 11-19, and >19 minutes (duration) respectively . After adjustment for Cardiovascular Disease (CVD) risk factors, participants experienced a 63% reduction in risk for Sudden Cardiac Death (SCD) in the highest sauna bathing frequency group (4-7x/wk) when compared to participants who only reported sauna bathing 1x/wk. The study showed similar reductions in risks for CVD, Coronary Heart Disease (CHD) and all-cause mortality as well.
An inverse relationship was also observed between sauna bathing session duration and risk of SCD, with a 52% reduction in risk being associated with the highest duration group (>19 minutes per session). Likewise, significant inverse relationships were found between duration of sauna bathing and CHD and CVD mortality. Finally, frequency of sauna bathing, but not duration, was also inversely associated with all-cause mortality, with a 40% reduction comparing 4 to 7 sessions vs 1 session of sauna bathing per week . To be clear, the study showed an inverse relationship between frequency and duration of sauna bathing and sudden cardiac death, fatal coronary heart disease, fatal cardiovascular disease, and all-cause mortality.
Another study involving 1935 Caucasian men (aged 42-61 years old) found frequent sauna baths may be associated with a reduced risk of acute and chronic respiratory conditions. During a median follow-up of 25.6 years the study showed a 27% and 41% reduction in risk in individuals who had 2-3 and ≥4 sauna sessions per week respectively compared with participants who only had ≤1 sauna session per week.
Furthermore, a study consisting of 2084 men (42–60 years of age) looked at sauna bathing and inflammation. Inflammation was measured by serum levels of C-reactive protein, a common biomarker of systemic inflammation. There was a notable inverse relationship between the frequency of sauna bathing and the levels of C-reactive protein. Frequency was grouped as 1x per week, 2–3x per week, and 4–7x per week with the highest frequency group being associated with the lowest levels of inflammation .
As you can see, there is a significant amount of research demonstrating the efficacy of heat therapy with frequency (session per week) being the most important factor. As I have already indicated, saunas and steam rooms are commonly found in many commercial and upscale training facilities which creates an opportunity to incorporate them as a lifestyle ritual. Exercise + Sauna Bathing; moreover, this combination of cardiovascular training (exercise) and frequent sauna bathing was associated with a substantial risk reduction in fatal cardiovascular and all-cause mortality events when compared to cardiovascular training and frequency of sauna bathing alone, concluding that the combination yields greater reductions in risk.
Now, I should also note there are some situations in which sauna bathing is contraindicated (not recommended). Unstable angina pectoris, recent myocardial infarction, and severe aortic stenosis are all situations where it is recommended to discuss the risks and benefits with your physician before starting any heat therapy 
Points to remember:
Sauna bathing 4-7x/wk for 11-20 minutes at 85-100C is associated with,
- Reduction in CVD risk
- Reduction in CHD risk
- Reduction in SCD risk
- Reduction in all-cause mortality
- Improved markers of inflammation
- Reduction is respiratory disease risk
 Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events. Full article.
 Sauna bathing reduces the risk of respiratory diseases: a long-term prospective cohort study. Abstract.
 Sauna bathing and systemic inflammation. Abstract.
 Joint associations of sauna bathing and cardiorespiratory fitness on cardiovascular and all-cause mortality risk: a long-term prospective cohort study. Abstract.
 Benefits and risks of sauna bathing. Abstract.