There’s been a lot of buzz lately around the purported health benefits of infrared saunas, with many people suggesting they’re better than traditional steam saunas. I wanted to find out what the hype is all about, so I decided to research the scientific evidence behind red and infrared light therapy.
Additionally, I decided to get the Sunlighten Solo — a portable far infrared sauna — so I could see first-hand how effective infrared sauna baths are for recovery, stress management, calorie burn, weight loss and more.
To learn more about the infrared sauna I’ve been using, check out my full review of the Sunlighten Solo.
The History of Saunas
While nobody knows exactly when humans started using saunas, there’s written evidence of an early Finnish sauna that dates back to 1112. Since then, the popularity of saunas has exploded.
I grew up in Austria, and when I was a professional athlete in my early 20s, steam saunas were a regular part of my recovery regimen (especially during the colder months of the season).
At the time, I didn’t fully understand the purpose of intentional heat exposure. I just thought that saunas make you sweat out any bugs that might be lingering inside of your body, helping you feel better and avoid sickness.
Of course, that was a somewhat simplistic view of the subject. But it wasn’t entirely wrong.
Hormesis: What Doesn’t Kill You Makes You Stronger
One of the reasons why saunas are so beneficial to your health is because they trigger hormesis, a mechanism that enables your body to adapt to a stressor so that you become stronger as a response.
One great example of hormesis that everyone is familiar with is exercise. Performing a physical activity can be a stressor, especially if you push your body to its limits. In response to this stress, your body adapts by growing new muscle tissue, expanding your lung volume or by making your heart stronger so that you can better handle such stressors in the future. It’s how you improve your physical performance.
The same principle applies when you jump into a sauna and expose yourself to temperatures your body isn’t used to.
That adaptation is likely what the ninth century German philosopher Friedrich Nietzsche alluded to when he said “What doesn’t kill you makes you stronger.”
Now that you understand the basic principle of hormesis, let’s talk about how infrared technology works. Then we’ll dive into the scientifically-proven benefits of sauna use and the differences between traditional steam and infrared saunas.
How Infrared Technology Works
Infrared light is part of the natural electromagnetic spectrum, wedged between visible light and microwaves. In other words, infrared light is invisible. However, depending on its wavelength, you can feel it as heat.
The infrared light spectrum is divided into near (NIR), mid (MIR) and far (FIR), depending on photon wavelength (frequency) and how much energy those photons carry.
For example, your TV’s remote control uses near infrared technology, which you can neither see nor feel. On the other side of the spectrum is far infrared, which you can actually feel as radiant heat.
The way infrared technology works is relatively simple: depending on its wavelength, infrared light penetrates the skin and nudges cells to stimulate warmth, growth and release, resulting in the many benefits we’ll discuss below.
The way it technically works is that the infrared light stimulates light receptors inside the mitochondria. Remember, the mitochondria is like a power plant inside each cell; normally, the energy your cells use comes from glucose or ketones, but light can be used as well.
By the way, did you know that approximately 50% of the sunlight that reaches Earth is infrared light?
That’s one of the reasons why regular sun exposure (without sunscreen) is so important for maintaining optimal health: sunlight influences the production of Vitamin D, and it positively influences your circadian rhythm and mood (among other things).
Of course, sunlight also includes ultraviolet waves that carry more energy than infrared light. That’s why you have to enjoy sunlight responsibly: getting too much of it can cause sunburn, which can in turn lead to skin cancer.
Most of the infrared saunas on the market today use heating technology that’s based on far infrared radiation to make you sweat and to support your overall health.
The Sunlighten Solo* sauna I have at home falls into this category.
That’s because far infrared light can penetrate both the epidermis and the dermis (the two outermost layers of the skin) and reach all the way into the fat-rich subcutaneous tissue (also known as subcutis or hypodermis) where your sweat glands are located.
In fact, studies have shown that far infrared radiation can penetrate up to 1.5 inches (4 cm) below the surface of the skin. Mid infrared light can only penetrate your soft tissue (dermis), and near infrared light is limited to penetrating your epidermis.
As a result, near infrared light is great for improving skin health, stimulating mitochondria, speeding up wound healing and increasing collagen production.
Top 10 Benefits of Infrared Saunas
1. Relieves Stress and Tension
The reason most people feel better after a sauna session is because heat exposure elevates serotonin levels. Studies have even shown that a single sauna treatment can improve the symptoms of major depression for as long as six weeks.
It’s worth noting that the stress induced by an infrared sauna does temporarily raise cortisol levels. However, thanks to the mechanism of hormesis, consistent sauna use helps the body adapt, thus lowering cortisol levels in the long run (as demonstrated in this study performed on young women).
Scientific evidence aside, I feel relaxed and at peace with the world every time I emerge from a sauna. It’s as if any tension I have melts away in the heat. That’s one of the reasons why I enjoy regular sessions in my infrared sauna (and my wife feels the same way).
2. Improves Recovery and Circulation
The heat from an infrared sauna causes your blood vessels to dilate, thus increasing blood flow and improving circulation. As a result, your heart can pump more nutrients and oxygenated blood to the parts of your body where they’re needed.
In fact, one study has shown that a single infrared sauna treatment can increase blood flow of the brachial artery by 68% after only 15 minutes. Additionally, the study shows that blood flow can remain elevated for as long as 30 minutes after the treatment.
This improved blood flow and nutrient delivery speeds up muscle recovery.
Remember, muscle recovery is all about improving blood flow. That’s why percussion massage guns and electric muscle stimulation devices are so effective: they increase blood flow to the treated areas.
Infrared saunas improve blood flow throughout your entire body. In fact, a study published in the Journal of Athletic Enhancement concluded that far infrared heat improved neuromuscular performance of pro athletes by increasing their testosterone/cortisol ratio. As a result, those athletes were able to recover quicker between training sessions. Another study demonstrated that infrared light can increase blood flow in the brain.
I’ve been using my infrared sauna to recover quicker after intense workouts and I’ve noticed less soreness (especially after lifting heavy weights).
3. Offers Temporary Pain Relief
I apply heat any time I suffer from muscle or joint pain after intense workouts, because increasing the flow of oxygenated blood to the affected area temporarily relieves pain.
As I explained above, infrared saunas dramatically increase blood flow because they can penetrate your tissue deeper than regular saunas or a hot bath.
As a result, bathing in an IR sauna is an excellent way to reduce pain and inflammation.
4. Mimics a Cardiovascular Workout
During my first session in our far infrared sauna, I told my wife that I noticed a significant increase in heart rate due to the stress induced by the infrared heat.
As a result, spending 30 minutes in an infrared sauna mimics a light to moderate cardiovascular workout.
During one of my recent sauna sessions, I decided to record my heart rate using Apple Watch and WHOOP Strap. As you can see in the graph above, my heart rate increased to 101 beats per minute, averaging at 86 bpm until I got out of the sauna.
That’s roughly the same heart rate that I would have during a brisk walk.
Note that the increased heart rate and lower blood pressure caused by infrared saunas means they might not be ideal for all individuals. See the side effects section below for more information.
5. Burns Calories (Weight Loss)
As a result of the increased heart rate, your body also increases its metabolic rate, thus burning more energy in the form of calories.
To find out roughly how many calories one session burned, I used my Apple Watch and WHOOP strap to record the sauna session as a workout.
Based on the findings from both fitness trackers, I burned approximately 177 additional calories during my 30-minute sauna session. That’s not too bad considering that I didn’t have to move a finger.
While burning extra calories can certainly support your weight loss efforts, keep in mind that much of the weight you’re losing during a sauna bath is water weight (because of how much you sweat).
More importantly, note that losing weight is a byproduct of a healthy lifestyle that involves a species-appropriate diet for humans, sufficient sleep and other factors. You can learn more about that in my article about how to live a healthy lifestyle.
6. Increases Resistance to Illness
As I was growing up, I was told that regular sauna sessions reduce your chances of getting sick. At the time, I didn’t really understand why, but I assumed it was because you’re sweating out any viruses you might be harboring.
That’s not literally how it works. Instead, an infrared sauna increases your core body temperature, tricking your immune system into thinking that you’re running a low-grade fever — a condition called hyperthermia.
Hyperthermia describes a condition of having a body temperature greatly above normal, whereas hypothermia is defined as having a body temperature below 35 degrees Celcius.
Additionally, studies suggest that the increase in body temperature causes the release of heat shock proteins that deter viruses from reproducing and reduces the amount of inflammatory cytokines.
One study even suggested that using a sauna can reduce your chances of catching a common cold by 50%. While colds aren’t usually life-threatening, they can have a major impact on your productivity.
I recently had a head cold (before I got my IR sauna) and the combination of congested sinuses and coughing was a major drag on my productivity. As a result, I’ll prioritize sauna use going forward (especially during the colder months of the year).
7. Helps to Get Rid of Toxins (Detoxification)
Besides helping regulate your core temperature, sweating is one the body’s preferred methods for getting rid of toxins, with respiration (breathing) and elimination (urine) being the other two.
That’s why sauna use is an excellent way to naturally detox your body. By sweating profusely, you flush out toxins such as heavy metals.
Based on a comprehensive review of heavy metal detoxification by renowned detoxification expert Dr. Dietrich Klinghardt, far infrared saunas are an excellent way to rid the body of heavy metal contamination because “infrared mobilizes specific toxins, like mercury, in deeper tissues.” In other words, infrared saunas may be more effective at eliminating toxins than traditional steam saunas.
8. Helps Lower Blood Pressure
Based on a study conducted by researchers at the University of Missouri, using an infrared sauna three times per week for 30 minutes each session lowered the systolic and diastolic blood pressure of participants.
The mechanism behind that is relatively simple: sauna use dilated blood vessels, thus lowering blood pressure.
The same study also concluded that repeated thermal therapy can improve vascular endothelial function (the ability of your blood vessels to relax and contract) in patients with coronary risk factors, such as atherosclerosis.
Because of that, the researchers recommended making sauna therapy a part of the treatment protocol for such patients.
I use my infrared sauna to keep my blood vessels healthy. Think about it like this: every time you expose yourself to infrared heat, you exercise your blood vessels by making them dilate (and then contract when you get out of the sauna). That’s like a workout for your blood vessels that helps them remain flexible and reduces the chances of developing atherosclerosis or similar artery diseases.
9. Helps Build Muscle and Increases Flexibility
The use of red and near infrared light (generally known as photobiomodulation) can not only decrease inflammation and oxidative stress but it can also increase muscle mass gained after training.
In other words, you’re not going to turn into the Hulk by using your infrared sauna every day, but if you do it in combination with your regular workout routine, you’ll likely see greater gains in muscle mass than without, based on this review of 46 clinical trials on the subject.
Additionally, a study conducted by researchers at Auburn University concluded that using Sunlighten’s mPulse full-spectrum infrared sauna increased the flexibility and range of motion of study participants by up to 300%. The increased range of motion led to better joint mobility, less friction in the joints and diminished stiffness.
That’s really incredible, but it’s worth noting that those stretches were performed during sauna sessions and during times of increased blood flow.
10. Improves Skin Health
I’ve heard people say that using an infrared sauna has anti-aging benefits. Unfortunately, that doesn’t mean regular sauna use can turn back your biological clock. However, there is scientific evidence that red and near infrared light in the 611-650 and 670-850 nanometer (nm) spectrum has a positive impact on skin renewal, cell health and tissue growth.
Specifically, wavelengths of exactly 633 nm and 830 nm can easily penetrate the skin, where fibroblast cells absorb the light to stimulate the production of collagen and elastin — two components that can help improve skin health and make you look younger.
Coincidentally, my wife started using SolaWave* several months ago; it’s a red-light therapy tool that’s supposed to improve the complexion of her skin, and based on the before and after photos we took (see above), the technology appears to be working.
The Limits of Infrared Saunas
Despite all the benefits of infrared saunas, they’re not a miracle tool that will magically make you look 20 years younger, cure your arthritis or remove all of the toxins your body has stored due to poor lifestyle choices.
I consider infrared saunas to be a positive stressor — much like fasting, exercise or an ice bath — that can help me become more resilient through adaptation and immune system support, recover quicker after intense workouts, support my skin health and more.
They’re one piece of the puzzle that makes up my healthy lifestyle.
Don’t make the mistake of living an unhealthy life filled with over-processed junk food, poor sleep and a lack of exercise (just to name a few bad habits) and then expect your infrared sauna to mitigate all of that.
Any positive intervention, including sauna use, can likely mitigate some of the negative factors in your life. But if you want to make a real dent, you have to make the right choices in all areas of your life, including nutrition, sleep, stress management and exercise.
You can learn more about what I mean by that and what changes I’ve implemented as part of my wellness journey in this article.
Infrared Sauna Safety and Potential Side Effects
The light emitted by infrared saunas is generally safe, but there are a few potential side effects to consider.
Infrared Saunas Stress Your Cardiovascular System
Infrared saunas stress your body and cardiovascular system by applying energy (in the form of heat) to your cells. While I consider that good stress (much like exercise or fasting), it can be overwhelming if you’re already stressed out or if your body is fighting a disease.
That’s why I don’t use a sauna, jump into my cold plunge or fast on days when I feel run down — I want to give my body ample opportunities to recover without piling on additional stressors.
Additionally, I would talk to your doctor before using an infrared sauna if you suffer from low blood pressure or have other cardiovascular conditions.
Your Perception of Heat Might be Different Than Mine
Everyone has a slightly different perception of heat. The temperature you set your infrared sauna to, and the time you spend in it, might be different from someone else. For example, my wife has no issues staying in our Sunlighten Solo far infrared sauna for 30 minutes or longer on its highest settings. I feel like I want to get out after about 20 minutes. 30 minutes is pushing it for me.
On the flip side, I have no issues spending a couple of minutes in ice cold water, whereas my wife can’t handle more than a few seconds.
If hormesis (adapting to stressors like infrared heat) is your goal, allow your sessions to become uncomfortable while also staying safe. You don’t want to spend an hour in an infrared sauna if you feel like you’re going to pass out due to heat exhaustion.
Can Infrared Light Harm Your Eyes?
Additionally, I’ve read studies that suggest near infrared radiation — such as the type that glass, iron and steel workers are exposed to — can damage the eyes by causing cataracts and other issues. That has led some people to think that full-spectrum saunas that emit near infrared light can also damage the eyes.
Obviously, you can’t compare subjecting yourself to a 30-minute sauna session that exposes you to low-temperature near infrared radiation with a job welding steel eight hours a day for 40 years. As is so often the case, the dosage makes the poison.
For example, daily exposure to sunlight is incredibly important to your health, but if you stay in the sun for hours without wearing sunscreen, it’ll damage your skin and you might develop cancer in the long run.
The same principle applies to exposing yourself to the full spectrum of infrared light. As you might remember from the beginning of this article, IR light makes up over half of the light emitted by the sun.
Infrared Saunas vs. Traditional Saunas
Steam saunas heat the ambient air (and your skin) from the outside, whereas infrared saunas carry energy through your skin to heat you from the inside.
As a result, steam saunas usually have to be hotter than infrared saunas to achieve similar benefits.
For example, the Finnish saunas I used as a professional athlete often reached temperatures of over 100 degrees Celsius (212 F). On the other hand, my infrared sauna tops out at 150 degrees Fahrenheit.
The advantage of infrared saunas is that they achieve the same core benefits (e.g., improved circulation, increased heart rate, etc.) as steam saunas, but with lower temperatures. That means you can likely spend more time in an infrared sauna than in a steam sauna.
Additionally, full-spectrum infrared saunas offer benefits such as skin rejuvenation and collagen production in your epidermis (thanks to the near infrared light) that traditional saunas do not.
Personally, I think you can get great benefits from either type of sauna, but I prefer the lower maintenance requirements of infrared saunas.
I talked to some of my friends and they swear by steam saunas because they like both the humidity and the ritual of pouring water over hot stones to generate steam. I get that, and it’s what I grew up with. But from a practical perspective, I prefer turning on my IR sauna through the push of a button, and not having to worry about ventilation and other issues associated with high humidity environments.
Infrared Sauna Benefit List FAQs
Are infrared saunas dangerous?
Infrared saunas are generally safe but there are a few considerations, as I discussed above. Make sure to drink plenty of water before and after using an infrared sauna to avoid dehydration. I’d also recommend avoiding sauna sessions at high heat on days you feel run down, because infrared light can be a stressor.
Do infrared saunas emit electromagnetic fields (EMFs)?
Yes, infrared saunas emit electromagnetic fields (EMFs) and electromagnetic radiation (EMR). In fact, all light (visible or otherwise) is part of the electromagnetic spectrum.
What’s important is that you check with the manufacturer of your sauna brand to see how the level of EMFs their sauna emits. Sunlighten (the brand I’m familiar with) has all of its saunas checked by third-party labs to ensure low EMF emissions. You can learn more about the test results on this page.
How often should you use an infrared sauna?
I use my infrared sauna several times a week, and I combine that use with taking cold plunges. In the end, it’s up to you how often to use your infrared sauna. I try to avoid getting used to it too much, because if I do, it becomes less effective from the perspective of hormesis. That’s the same reason why I don’t fast, do CrossFit or take a cold plunge every day. I want to keep my body “on edge” so I continue adapting and become more resilient.
Can I use an infrared sauna twice a day?
You could, but I don’t think you’d get twice the benefits. In fact, it might even be counter-productive for most people. More isn’t always better. Instead, you want to find a sweet spot.
Think about it: you also wouldn’t work out twice a day, unless you have a specific goal in mind that requires you to push your body to its limit for a while. But if you do, make sure you allow for ample time to recover afterwards.
How often should you use an infrared sauna for weight loss?
You can enjoy an infrared sauna several times a week when combined with proper lifestyle choices that are the primary driver behind losing weight.
In other words, if you don’t follow an appropriate diet that’s centered around the very foods humans have eaten for millions of years (one that’s devoid of industrial seed oils and processed junk food), paired with quality sleep and regular exercise, then using an infrared sauna will likely not deliver the results you’re looking for.
As I mentioned above, I burn less than 200 extra calories during a 30 minute-sauna session. While that’s not bad considering that I didn’t have to be physically active for it, it’s also not a whole lot if your dietary lifestyle includes high-calorie junk food with low nutrient density. For example, a Pumpkin Spice Frappuccino from Starbucks has between 290 and 510 calories (depending on the size).
That’s why I keep saying that weight loss is a byproduct of a healthy lifestyle that infrared saunas can be a part of. But don’t expect an infrared sauna to compensate for poor lifestyle choices made on a daily basis.
Can infrared saunas burn your skin?
Yes, depending on your sensitivity to heat and how close you get to the heaters, infrared saunas can burn your skin or cause irritation. However, I’ve never gotten any burns in my Sunlighten Solo sauna, even though I’ve touched the heaters several times (mostly on purpose to see how hot they get).
Can an infrared sauna help with chronic pain?
An infrared sauna session increases blood flow, which can temporarily reduce pain. The increased blood circulation can also speed up wound healing and recovery. However, it’s important that you identify and fix the root cause of your pain, because that’s not something an infrared sauna can do.
Do infrared saunas help treat psoriasis and other skin conditions?
It’s important to understand that psoriasis is an autoimmune inflammatory skin disease, caused by a dysfunctional (overactive) immune system that attacks healthy skin cells.
I’m a firm believer that autoimmune conditions are caused by lifestyle factors, including poor dietary choices and exposure to environmental toxins. Because of that belief, my first course of action would be to remove all inflammatory foods (predominantly plants) and environmental toxins from your diet and environment. If you do that, chances are your skin issues will resolve themselves.
Using an infrared sauna can be an excellent tool to support these efforts, but you still have to remove the root cause of your condition.
There are some studies that suggest that phototherapy using different wavelengths can help with the treatment of psoriasis, eczema and other skin conditions.
What are full-spectrum infrared saunas?
In contrast to far infrared saunas, which emit only a portion of the infrared light spectrum, full-spectrum infrared saunas include heaters that emit a combination of near, mid and far infrared light. Unfortunately, full-spectrum infrared saunas are relatively rare. One model is the Sunlighten mPulse 3 in 1*, which I have my eyes on.
Wrap-Up: Infrared Sauna Benefits
Based on everything I’ve learned about infrared light and infrared saunas, as well as the positive experience I’ve had with my Sunlighten Solo far infrared sauna, I highly recommend phototherapy as a wellness tool.
Infrared saunas are certainly not a cure for every disease known to mankind, but they do provide plenty of scientifically-validated benefits, making them worth your consideration.
I jumped onto the infrared sauna bandwagon at the end of 2021 and have been enjoying my daily sauna sessions, combined with regular cold plunges, ever since.
Do you have a sauna at home, or are you considering getting one? If so, what are your thoughts on steam vs. infrared? Let me know by leaving a comment below.
I’m a healthy living and technology enthusiast.
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Top 10 Benefits of Infrared Saunas That May Surprise You is written by Michael Kummer for michaelkummer.com