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The Finnish people have known all about sauna benefits for years, and the rest of the world is finally starting to catch on!
After spending time in Finland, daily sauna use is a regular part of my routine, and years of scientific research back this practice.
What Is a Sauna?
Many traditional cultures used heat therapies for healing for thousands of years, dating back to the Mayans (2000 BC), and ancient Greecians and Romans (300 BC). Nowadays, sauna use is engrained in many cultures, from the Finnish saunas to the Swedish bastu, the Russian banyas, the Korean jjimjilbangs, and the Japanese sento.
The term “sauna” can refer to any type of small or large room or device designed to help the user experience dry heat or wet heat (steam). There are now also infrared (far and near) saunas that emit infrared light and claim to heat the body more effectively.
Types of Saunas
There are multiple types of saunas, including:
- traditional dry saunas, which can be heated with fire, hot stones, gas, or electricity (popular in Scandinavian or Finnish culture)
- steam saunas, where you can generate steam by applying water on the heating element (often found in spas and gyms)
- infrared saunas, which use invisible light within certain frequencies to penetrate and heat up the body’s tissues directly (smaller home units are available)
Infrared saunas can further be broken down in to 3 types:
- near infrared saunas
- far infrared saunas (often abbreviated FIR)
- full spectrum infrared saunas
Infrared Sauna vs Traditional Sauna
The infrared sauna is a more recent invention as it can only operate with electricity. In the 1800s, Dr. John Harvey Kellogg from Michigan put together what he called an “electric light bath” from light bulbs, right around the time that light bulbs (which emitted a lot of near infrared light) were invented.
After he presented his invention at Chicago World Fair, a German entrepreneur saw the device, replicated the design and sold it all over the globe because of its powerful healing abilities. It was said that this device cured the gout for the King of England!
How Infrared Saunas Work
While traditional saunas heat the air to heat the body, infrared saunas use invisible light just below red light frequencies to penetrate and heat up the tissues directly, to a depth of up to 1.5 inches into the skin. Although our eyes can’t see it, we can feel it as gentle, radiant heat.
The mechanism by which infrared saunas work is called photobiomodulation … a big fancy word meaning a form of therapy that utilizes light.
What Is Photobiomodulation?
According to quantum physics, molecules can be excited by specific light frequencies. (The higher frequency the light is, the more energy it carries.) The “excited” molecule then goes through a process to release the energy and return to its normal state, typically in the form of light at a lower frequency.
You can observe this process happening everyday inside of a fluorescent lamp, when a UV light excites chemicals coating the inside of the bulbs to emit visible light.
Photobiomodulation is when living organisms utilize this process. This is where the distinction between near and far infrared comes in:
Near Infrared Saunas
Higher frequency red light and near infrared light (0.8 – 1.5 µm) can excite energy-producing enzymes in the mitochondria, the powerhouse of the cell. This increases mitochondria function and initiates many healing processes inside the cells, including increasing cellular energy (ATP) production, reducing oxidative stress, and reducing inflammation. (This article discusses more about the specific benefits of near infrared.)
Far Infrared Saunas
While scientists are still trying to understand why the far infrared spectrum has so many health benefits, this light spectrum has more clinical studies supporting its benefits over other infrared bands.
Rather than exciting mitochondria enzymes, far-infrared light (5.6–1000 µm) affects the health of the cells by exciting water molecules. Aside from producing heat, far infrared may also increase mitochondria function by structuring the water molecules that surround the mitochondria.
Which Sauna Is Best?
The research is still out on this. Most of the studies are done on traditional saunas and seem to indicate the heat is the main mechanism of benefit. At the same time, many companies claim that infrared saunas have additional benefits, though we’re still waiting on studies to prove this. Infrared saunas are often much less expensive and easier to fit into a home environment, making them a more reasonable option for most of us.
The Health Benefits of Saunas
So, why would one swelter in a sauna? I find it pleasant but not everyone has the same level of heat tolerance (more on that below). It turns out heat and sweating alone have many positive health benefits. According to Dr. Rhonda Patrick, the benefits of heat conditioning in a sauna include:
1. Heart Health & Blood Pressure
A review of all of the published scientific literature about saunas shows a strong trend of coronary benefits, most notably in their ability to help normalize blood pressure and reduce the chance of congestive heart failure. In fact, a Harvard review of data showed a potential 40+% reduction in heart attack risk from using a sauna 4-7 times per week. And the benefit went up with increased use. In other words, the study showed that the more often and the longer amount of time a person uses a sauna, the more benefit and on average, the longer that person lives.
Heat conditioning or sauna use resembles cardiovascular exercise in many ways, because the cardiovascular system has to work harder to eliminate the heat. Not only does it increase blood flow, sweating, and cardiovascular fitness, but it also leads to a post-exercise euphoria where you feel relaxed, happy, and experience less pain.
2. Sweating and Detoxification
An increase in circulation and sweating can aid in detoxification, and in this way sauna therapy helps the body’s natural process of detoxification through sweating.
There is also some evidence that sweating might help reduce heavy metals in the body. A systematic review in 2012 found that toxic heavy metals like arsenic, cadmium, lead, and mercury are found in sweats of people who are exposed to these harmful metals. In a case report, they found that mercury levels normalized with repeated sauna treatments. Again, this benefit is likely due to the sweating and not any special mechanism of the sauna itself.
3. Pain Relief and Muscle Recovery
Saunas increase heat shock proteins, antioxidant enzymes, and stimulate cellular cleanup (autophagy), which can help our cells function like new. In aging mice, an increase in heat shock proteins help delay aging and improves cognitive function.
Sauna bathing can also increase several anti-aging hormones including human growth hormones and the insulin-growth factor 1. IGF-1, in particular, can really help with injury healing.
Several heat-shock proteins can even help with increasing muscle mass, even without weight training. Through photobiomodulation, infrared therapy has a powerful anti-inflammatory effect that can accelerate injury healing.
This is the reason that many people, including Lady Gaga, turn to saunas for pain relief.
4. Mood and Cognitive Function
Just as when you go for a run, sauna use increases endorphins (the happiness hormone) and opiods (the body’s natural pain reliever), as well as a molecule called brain-derived neurotrophic factor (BDNF) in the brain.
BDNF stimulates neurogenesis (the growth of new neuronal cells) in the brain and protects new neurons from damage. Improving BDNF levels is therefore important for cognitive function. In addition, low or abnormal levels of BDNF may be a cause of several mental and psychiatric diseases.
Infrared saunas can also reduce stress by re-balancing the stress response axis. It can help lower cortisol, and thus helps with stress-related health problems. Saunas also improve the neurotransmitter called norepinephrine, which can help improve cognitive performance.
5. Weight Loss and Metabolic Health
Contrary to popular claims, heat and sauna use do not directly burn fat or kill fat cells. However, saunas can help improve insulin sensitivity, increase lean muscles, and reduce fat by changing the hormonal environment. In addition, the saunas also reduce inflammation. Therefore, sauna therapies can prevent obesity, diabetes, and cardiovascular diseases.
A Japanese study found that two weeks of sauna therapy increased appetite and food intake in people of a healthy weight. However, in overweight people, far infrared sauna usage together with a low-calorie diet resulted in significant weight and body fat loss. While this study did not compare the fat loss with a group that did not use the sauna, the reduction in body fat (4.5%) in about two week’s time is considered very fast.
6. Help for Inflammation
As mentioned above, sauna use may increase the presence of heat shock proteins, which are anti-inflammatory. For this reason, saunas may help lower chronic inflammation. Since inflammation is connected to almost every major disease, this is a big deal!
Study participants who used saunas regularly shower lower levels of oxidative stress, even within two weeks! Another study found that men who used the sauna 4-7 times a week had 32% lower levels of c-reactive protein (CRP).
According to Dr. Michael Breus, a clinical psychologist with a board certification in sleep medicine, the steep drop in body temperature at night is one of the circadian cues that the body takes that it is time to sleep. This explains why a warm bath or a shower before bed can improve sleep quality. Because the sauna typically heats the body up much hotter than a warm shower, it can take the body a few hours to cool down for bed. In order to improve your sleep quality, consider using a sauna session in the afternoon or before dinner in order to allow the body to cool down by bedtime.
A Japanese study also found that far-infrared ray exposure improved sleep quality in both rats and an insomniac human subject.
8. Skin Health
In order to eliminate heat, your body increases blood flow to the skin. In addition, the skin adapts to this process, making it healthier. A German study found that the skin of regular saunas users could better hold moisture and maintain a healthy skin pH. In addition, these sauna users had less sebum on their foreheads, suggesting that they were less likely to get acne.
Skin problems like eczema and psoriasis involves both inflammation and a vulnerability of the skin barrier. By helping both with strengthening the skin barrier and reducing overall inflammation, infrared sauna, if tolerated, can really help with these skin issues. (If sweat significantly irritates the rash, then you may want to protect the rashes with a eczema-friendly lotion and shower right after the sauna.)
Risks & Cautions for Sauna Use
Though sauna use is generally considered safe, anyone considering sauna use should absolutely check with a doctor or medical professional first, as some people (including Tim Ferriss) have genetic conditions that can lead to overheating and health problems from sauna use.
Common sense cautions also include avoiding direct contact with heating elements to avoid burns, not using a sauna for more than the recommended amount of time, or using a sauna after alcohol use or exercise.
Anyone new to sauna use should start off gently at a lower temperature and shorter periods, and gradually increase the temperature and duration of sauna use. Take breaks or finish if you don’t feel well. Remember to hydrate and replace electrolytes accordingly during and after your sauna session.
Safe for Pregnancy?
While there are concerns that heat exposure may harm babies in utero, studies show that saunas typically do not pose problems in healthy pregnancies. I certainly saw many pregnant moms in saunas in Finland, but because every pregnancy is different, it is best to check with your doctor or midwife first.
How to Get the Benefits of a Sauna
Here’s the thing … saunas are pricey and they aren’t for everyone. After researching the health benefits, it became a priority for us to make room in the budget for a sauna, but it certainly isn’t a small decision!
Our local gym had a sauna, but we realized that by the time we paid for a gym membership for my husband and I (that included childcare), we could buy much of the equipment we’d be using instead over the course of a couple of years. So instead of going to the gym for sauna use and working out there, we now have a low-EMF infrared sauna in our home and have purchased workout equipment we actually use (kettlebells, free weights, pull up bar, etc.).
Focus on the Heat
Since the most beneficial part of the sauna is the heat itself, we worked up to spending as much as half an hour in it at one time. The sauna is super relaxing and it has been beneficial for my skin as well! I jokingly call the sauna my “quiet box” and often listen to podcasts while I’m in there. I enjoy it so much, that I’ve even recorded podcasts in it!
There are several companies that offer at-home infrared saunas:
- Clearlight: Offers full-spectrum, low-EMF saunas. They have various models from a 1-person up to custom whole room saunas. (Call them and let you know I referred you and you should get a discount).
- Sunlighten: Another trusted name in infrared saunas with a variety of options. They have a portable one-person sauna (The Solo) that is much less expensive than wooden models and easier to store. If I feel myself getting sick I immediately spend an hour in there to induce fever.
- Healthmate: I’ve tried their sauna at a friend’s house and it seemed comparable and reached about 160 degrees. I haven’t been able to do further testing on it and they are not comfortable with me affiliate linking to them unless they are my only recommendation so I don’t have a referral or discount link for them to share.
Or get a traditional dry sauna:
If you prefer the more traditional Finnish barrel sauna, there are several different options to purchase here.
How Often Should You Sauna (& for How Long)?
Many Finnish people use the sauna daily, so saunas are generally safe to use on a daily basis for healthy people.
Most of the research agrees that as long as a person is healthy and can tolerate saunas, regular use can be beneficial. In studies, 4-7 sauna sessions per week (lasting at least 20 minutes) showed the biggest results in all of the above categories.
This article was medically reviewed by Dr. Scott Soerries, MD, Family Physician and Medical Director of SteadyMD. As always, this is not personal medical advice and we recommend that you talk with your doctor.
Do you use a sauna? What benefits have you noticed, if any?
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