Originating in Finland, saunas are popular among those trying to improve their fitness and overall health. Due to the amazing health benefits, sauna use has spread from the Nordic region to various places all around the world. Recently the anecdotal evidence of the benefits for sauna use are being studied and validated through research. New discoveries are also being made for potential unknown benefits as well as the mechanisms of sauna use leading to these benefits. 

Why Saunas Help

There are many potential mechanisms as to why the sauna may provide incredible benefits. One of the main reasons could be their ability to simulate the effects of exercise such as increased heart rate and elevated core body temperature. One difference between the body's response to sauna vs. exercise is that sauna causes a decreased workload on the heart while exercise increases it's total workload. These exercise-like effects of sauna use may be the reason for some of the amazing cardiovascular benefits. 

Another effect of sauna use involves the body's hormonal response. Heat stress in the form of sauna use increases a hormone called norepinephrine (noradrenaline). This hormone is used in the "fight or flight" response and is responsible for things like blood pressure control, blood sugar regulation, fat burning for energy. The heat stress from sauna use may also increase activity of neurotransmitters like serotonin and dopamine (1) which may be reasons for the improvements in mood and psychological state attributed to sauna use (2).

One of the more advanced effects of sauna use is the increase in chemicals in the body called heat shock proteins (1). These chemicals are released in response to stress and can have major benefits by stimulating the immune system and play a protective role against cancer, cardiovascular, neurodegenerative, and many other diseases (3). 

Benefits of Sauna Use:

1. Live Longer: 

In 2015 a major study on the association between sauna use and death came out in the Journal of the American Medical Association. The study found that with increasing sauna use frequency, the risk of dying from a sudden cardiac event (like a heart attack), coronary heart disease, and cardiovascular disease was decreased. The study also found that total risk of dying (all-cause mortality) was also decreased with sauna use. The results of this study were seen in a dose dependent manner and individuals who used a sauna the most (4-7 times per week) had the least amount of cardiovascular related deaths and all-cause mortality (4).  

2. Boost Your Immune System:

In addition to the immune-boosting effects of heat shock proteins (HSPs) that sauna use provides, HSPs have also been shown to have additional effects on circulating immune cells. Sauna sessions have been shown to increase the number of disease fighting white blood cells and other immune system markers (5). These immune system changes are not limited to a single session as repetitive exposures to lower-heat saunas have also been shown to further improve the immune system (6).

3. Decrease Inflammation:

As most people are well aware of, systemic inflammation is a driver of all types of disease including many metabolic diseases like insulin resistance, type 2 diabetes, high blood pressure, and cardiovascular disease (7). Studies have shown that increased frequency of sauna use is associated with decreased inflammation (measured serum C-Reactive Protein) (8). The ability of heat stress seen in sauna use to decrease systemic inflammation is a benefit on it's own as well as a possible contributor to many of the other health improvements attributed to sauna use.

4. Detoxify Your Body:

If you were to ask most sauna users why they use the sauna one of their answers will likely include "detoxification", "to get rid of the toxins", or even "to sweat out the alcohol". Although direct elimination of toxic substances like drugs and alcohol from sauna use may not directly be true, there is still some form of detoxification occurring during sauna use. Our liver and kidneys are our first line of detoxification but sweat may also be a route of toxin elimination. It has been shown that many toxic elements like lead, mercury, arsenic, and cadmium are excreted through sweat and sauna use may also reduce the levels of some of these substances (9). 

5. Improve Symptoms of Headache:

Sauna use has been shown to improve symptoms of the most common type of headache, tension-type headaches (10).

6. Improve Insulin Sensitivity and Blood Sugar Regulation:

Heat therapy in the form of sauna use may be an excellent tool to help with the treatment of diabetes and insulin resistance due to it's effects on blood sugar regulation and body weight (11) (more in #7)

7. Help with Weight Loss

This is one of the more common reasons that leads many people to begin using a sauna. Although much of the immediate weight loss from sauna use may be due to fluid loss in sweat, the exercise mimicking effects of sauna use (increased heart rate, etc.) will certainly burn calories. The inflammation-reducing and blood sugar lowering effects found in sauna users are likely due to heat shock proteins and the hormonal response (norepinephrine), which may also help with weight loss and fat burning (11)

8. Speed Up Recovery After Exercise:

There are a few ways that sauna can help you recover from an exercise session including elimination of muscle waste and acting as an antioxidant booster. When we exercise we create by-products from energy utilization and muscle use which our bodies need to clean up and eliminate. By using a sauna after exercise we are able to clear out some of these harmful products quicker and neutralize the free radicals more efficiently, leading to a faster recovery (12, 13). 

9. Improve Respiratory Function

Sauna use has been shown to improve respiratory function as well as reduce the risk of many acute and chronic respiratory diseases like COPD, asthma, pneumonia, and more (14). 

10. INcrease Muscle and Joint Movement & Decrease Pain:

Due to the increases in joint mobility and flexibility of connective tissues, sauna is an excellent tool that can improve flexibility and range of motion (15). Sauna may also have incredible effects on those with inflammatory muscle and joint conditions. Studies have shown regular mild sauna use to reduce pain and improve mobility in patients with arthritic conditions and also help some fibromyalgia patients decrease pain. It is important to note that sauna use may not be the best option for everyone with these conditions as some have experienced negative side effects, which may be prevented by proper cooling after use (16)

What is the Best Way To Sauna?

Many of the studies referenced used various different temperatures, durations, and frequencies. Some of them even had different types of saunas (infrared, wet sauna, etc.). Currently there is no consensus on what the best type, temperature, duration, and frequency is as it can vary from person to person. The most important factor when looking to achieve the benefits of sauna use is to use a temperature and duration that activates the body's heat response mechanism and allow for heat shock protein production, cardiovascular changes, and hormonal changes. For healthy adults, most of the research seems to be in the range of 160-210º F for 10-30 minutes, 3-5 times per week. 

Are there Any Dangers of Sauna Use?

As with anything, some people may not tolerate heat stress very well and may experience side effects, but generally sauna use is very safe and well tolerated for healthy adults and children. It is important to know your limitations when using a sauna and not push your body too far as extremely excessive heat stress may have some negative consequences. Contraindications to sauna use include those with heart conditions like unstable angina pectoris, previous heart attack, aortic stenosis, and some other conditions that may compromise your heat stress response (17).  As always it is important to ask your physician if you are healthy enough to begin using a sauna.