Sweat It Out – The Powerful Health Benefits of Saunas

In these cold winter days, what could be better than immersing yourself in the soothing heat and calm serenity of a warming sauna?  The good news is that saunas not only have the perk of chasing away the chills, but they have also been shown to provide an impressive range of health and longevity benefits.

Saunas originated in Finland several thousand years ago and over time were adopted in many other cultures, from the banya in Russia, to Islamic hammams and the Central American temescal sweat lodges.  Even today, saunas remain a big part of Finnish culture – there are estimated to be 2.4 million saunas in the country (which has a population of only 5 million people!).  And while the rest of the world isn't quite at that level, over the years saunas have also grown in popularity elsewhere, with many gyms, yoga studios and spas now offering sauna facilities. 

So why should we be stepping up our sauna game and getting the heat on more often? 

Saunas have been shown to have a positive impact on many aspects of health, from blood pressure and cardiovascular health, to immune function, detoxification and weight loss. This multitude of benefits stems from the effects on the body of short-term exposure to higher environmental temperatures. Dry saunas typically range from 70-90 degrees Celsius, while infrared saunas (more on these later) tend to be between 45-60 degrees Celsius. This heat elevates both skin and core body temperatures, activating thermoregulatory pathways and creating a mild stress on the body.  

Although counterintuitive (stress must be bad, right?), this stress response is actually beneficial as it initiates a bodily process called hormesis. Hormesis refers to the exposure to minor stressors which generate a disproportionately large compensatory response at cellular level, which in turn increases the body's resilience (other examples of hormetic stressors include exercise, fasting, cold water therapy and breathwork). 

The activation of thermoregulatory pathways initiates physiological responses such as sweating and increased heart rate, cardiac output and blood flow to the skin. At a cellular level, the process of hormesis due to heat exposure triggers the production of heat shock proteins which help with cellular repair, provide protection against cellular stress and prevent free radical damage. 

These responses play a role in the wide-ranging health benefits associated with saunas, including: 

Detoxification through sweating

One of the primary benefits of saunas lies in their ability to induce sweating. Our skin plays a fundamental role in detoxifying the body from the vast array of impurities and toxins we are exposed to in daily life.  Sweating, beyond being a natural cooling mechanism, serves as a powerful mechanism to support these detoxification processes.  As our body temperature rises, our sweat glands kick into action and support our bodies in expelling toxins, such as heavy metals, phthalates and BPAs, through secreting sweat. 

Cardiovascular health improvements

The heat from sauna exposure prompts blood vessels to dilate, improving blood circulation and promoting cardiovascular health. Studies have shown that a 30-minute sauna session can reduce blood pressure and improve arterial stiffness in those with one or more cardiovascular disease risk factors. Two separate small-scale studies of healthy females and healthy males in their twenties demonstrated a decrease in cholesterol levels after regular sauna use. The combination of sauna and regular exercise has also been shown to improve levels of cardiovascular respiratory fitness, which represents the body’s ability to deliver oxygen to muscles and organs during physical activity.  

Immune health support

Saunas also provide significant benefits when it comes to strengthening our immune system. The associated heat exposure has been found to increase the production of white blood cells, including lymphocytes and basophils, thereby bolstering our immune defenses and ensuring our bodies are better-equipped to ward off unwanted pathogenic invaders.  This is particularly helpful at this time of year when everyone else is being laid low with seasonal bugs.  These benefits were demonstrated in a German study which showed that participants having frequent saunas had significantly fewer colds when compared to the control group. 

Weight loss and metabolic health benefits

Sauna use has a beneficial impact on metabolic rate and has been found to reduce fasting glucose and cortisol levels in middle aged men. Studies have also shown that three 30 minute sauna sessions a week resulted in a reduction in body fat of 4% over a four-month period.  

Reduction in muscle tension

Saunas also increase blood flow to our muscles, delivering oxygen and nutrients that support muscle repair. The increased white blood cells also reduce inflammation which in turn reduces muscle pain. 

Longevity 

Sauna use has also been linked to increased lifespan, although from a longevity perspective, frequency is key. A 2015 study of over 2300 middle-aged men in Finland found that all-cause mortality was 40% lower in participants who took a sauna 4-7 times a week, compared to those who used a sauna once a week.   

Types of Sauna:

Finnish dry saunas 

The health benefits discussed above are primarily based on research focused on the use of classic Finnish dry saunas, the type typically found in traditional spa settings. These use dry heat, often generated by rocks or electric heaters, and involve higher temperatures and low humidity. 

Infrared saunas 

Infrared saunas are another type of sauna therapy. Their use has been increasing in popularity as research has evolved on the therapeutic benefits of infrared light exposure. In recent years, studies focusing on infrared saunas have indicated that these provide similar benefits to the more traditional Finnish-style saunas.  

What's the difference?

Infrared saunas use mid and far infrared light to generate heat. These are wavelengths of red light which are not visible to the naked eye but which penetrate deep into our tissues. These saunas operate at lower temperatures than Finnish dry saunas and work by heating your body directly, without warming the surrounding air, providing a more focused and penetrating heat.

When it comes to the associated health benefits, the mid and far infrared light wavelengths are thought to penetrate deeper into the body than the heat from traditional saunas, thereby helping to detoxify areas where toxins and heavy metals are trapped. Heat generated by far infrared wavelengths has also been shown to generate a small increase in human growth hormone production and to lower cortisol levels, aiding weight loss and stress management. 

Are there any cautions I need to be aware of?

Studies have shown use of saunas to have a strong safety profile. Anyone with low blood pressure should be careful, however, as any further reductions in blood pressure can result in light-headedness or dizziness. Those suffering from unstable cardiovascular issues, such as angina, are also advised to avoid saunas. One further caution is that saunas should not be used following alcohol consumption due to alcohol's dehydrating and blood pressure-lowering effects.

Ensuring good hydration through adequate water intake and use of electrolytes is also important alongside sauna use. 

Saunas are something I try to incorporate into my regular wellness routine. Not only do they provide the rejuvenating benefits discussed above, but they are also the perfect opportunity to slow down and take a tranquil, mindful moment away from work demands, screen time and every day stresses. Given the availability of sauna facilities in many gyms and wellness centres, it's usually not hard to find a sauna nearby. Some of my favourite spots in London are Ten Health & Fitness , Banya No. 1 and Triyoga .