*Disclaimer: The written article is based on a summary of existing literature on the topic of infrared saunas. The article is for educational purposes and the information provided below cannot be taken as a promise to help with acute health problems or diseases.
The claims in the article are backed by 20 scientific references. All references are numbered. You can access the text of the reference by finding the corresponding number in the reference list at the end of the blog post
One of the most important models in health is the “calories in, calories out” model in health science. The model entails that if you burn more calories than you consume per day, you’ll lose weight. If the opposite is true, and you take in more calories than you burn, you’ll gain body weight (1; 2; 3; 4)
(For this blog post, I’ll assume that this model is the correct fat loss model. Other models such as that argue that blood sugar disbalances and disruptions in the hormone that manages blood sugar, called “insulin”, are incorrect. (5 ; 6; 7)
The naturally emerging question is whether spending time in an infrared sauna burns calories. The answer is a resounding “yes”. The next question, of course, is "how many?" I'll give you a detailed breakdown and answer of the science in this blog post:
Question 1: Do You Burn Calories In An Infrared Sauna?
Before considering the question of “does infrared sauna burn calories”, I’ll first explore the concept of “calories”. Every adult has heard about calories but if you ask them to explain the concept, they usually won’t know exactly what it means.
So start with the definition so that we’re all on the same page:
“Calories” are simply a definition within Chemistry, and signify the amount of energy needed to increase the temperature of one gram of water by one degree Celsius (8)
Energy is primarily created in your cells (9; 10). Most of your cells contain hundreds to thousands of “mitochondria”. “Mitochondria” can be conceived as the energy-producing factories of your cells.
In your mitochondria, the food you ingest is finally converted into energy. Without going into too much detail, the calories you ingest from food are finally burned in your mitochondria. That energy-producing process allows you to survive and thrive.
The poorer that energy-creating process in your mitochondria becomes, the closer you’ll move to disease. And, the better that process becomes, conversely, the closer you’ll move towards health.
With that being said, you now understand the basics of calories and where they are burned. Let’s now turn the conversation to the topic of the calories infrared sauna connection:
Does Infrared Sauna Use Burn Calories? Yes - Here’s How
Different types of intermittent stress can increase the size and number of mitochondria in your cells (11; 12). Your body, therefore, becomes more efficient with the energy (calories) it takes in.
These types of intermittent stress include exercise, spending time in low-oxygen environments such as high mountains, and both low and high temperatures. The low temperature stressors such as cold showers and ice baths have become really popular in the last few years.
High-temperature stressors include hot baths, Finnish saunas, steam rooms, and infrared saunas, among others. During all of these activities, the body actively counters overheating. Energy needs to be spent to cool down your body, which then necessitates the burning of calories.
The magic question then becomes: “how many calories burned in an infrared sauna?” Here’s the answer:
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Question 2: How Many Calories Are Burned In An Infrared Sauna?
Many online sources make statements that you’ll burn “600 kilo-calories” per half an hour during a sauna session. Other claim that you’ll only burn 50 kilocalories per half an hour. The problem with these arguments is that they don’t directly look at weight loss studies.
The good thing is that several studies looking at weight loss and fat loss during sauna sessions exist (13; 14; 15). None of these studies is perfect but they do allow for you and me to get closer to the correct answer. Let’s therefore explore the studies I’ve just quoted:
Study 1: 400 Kilocalories Per 40-Minutes
Using a 10-minute sauna sessions alternated with a 5-minute cooldown period for 4 times, for a maximum of one hour, leads to a body weight loss of 1.45 pounds if you’re sedentary (16). Of course, much of that weight loss is water weight and is never exclusively fat mass because of sweating.
Fortunately, calories burned were also measured to paint a more complete picture. Per 10-minute session, 73-134 kilocalories are burned. Taking an average of 100 kilocalories, that’s 600 kilocalories during a 1-hour period.
One methodological issue in this study is that there are cooldown periods of 5-minutes between sessions. Later sessions showed an increase in calories burned, so a straightforward 30-minute or 60-minute sessions almost certainly burns many more calories than 400. Another limit of this study is that sedentary individuals with a higher body mass and lower heat tolerance are used - these individuals will burn more calories during a sauna session than people with a normal weight.
Let’s move to the second study:
Study 2: 495 To 1125 Kilocalories During 60 Minutes Of Total Sauna Time
A second study investigates how both male and female athletes respond to three 20-minute sauna sessions (17). A sauna temperature of 70 degrees Celsius is used, and participants get a 5-minute rest interval between the three sessions.
Fortunately, all participants were re-hydrated before being weighed again. That way, water losses can be separated from losses of other bodily tissues such as muscle and fat.
Women lost 0.88 pounds of body weight and men 1.98 pounds of body weight. The only downside of this study is that despite the rehydration efforts after a sauna session, the water weight of the participants didn’t return to normal.
But, assuming that just one-quarter of that weight loss originates from tissues, and half of that body mass consists of fat loss. In that case, women lose 0.11 pounds of body weight and men 0.25. If one pound of body fat consists of 4,500 calories (1 gram of fat contains 9 kilocalories), then you’ll burn between 495 and 1125 kilocalories per 60-minute session.
That’s quite a nice number if you integrate infrared sauna sessions as an almost daily habit. You can also expect heavier fat losses from an infrared sauna compared to a traditional one because an infrared sauna is better able to increase the core temperature of your body.
Do keep in mind that these numbers are an oversimplified estimation on my part, because differences in water weight prevented direct measurements of fat losses during this study.
Next up, let’s place these results into more context...
There’s more to the story though - let’s explore another mechanism:
Intermittent Stress - Such As Sauna Sessions - And Hunger
There’s more to the story of burning calories than just the time you spend in a sauna though. Temperature stress also gives you feelings of well-being and reduces hunger - at least that has been shown in animal studies (18). Human studies, while not universally agreeing, show the same picture (19; 20).
You’ve probably noticed yourself that you’re less hungry if it’s summertime. Not only does the body need fewer calories to stay warm, the body also actively lowers calorie intake to avoid overheating. Heat is a byproduct of the energy-creation process of your mitochondria. Therefore, slowing these processes down by decreasing hunger allows you to burn more calories overall.
Lastly, let’s put the discussion about how many calories burned in an infrared sauna in more context:
Factors Determining Calories Burned During Sauna Visits
There’s a lot more to the story though: not everyone burns the same number of calories during each sauna session. For instance, if you’ve got a higher body weight or are not adapted well to sauna visits (i.e., you have low heat tolerance), then visiting a sauna results in you burning more calories.
The human body actually tries to conserve energy because energy isn’t limitless. Elite athletes, for example, can perform more work while burning a lower number of calories. The same is true for sauna visits - the more experienced you get, the more calories you burn.
Conclusion: Calories Burned In An Infrared Sauna Are Hard To Exactly Determine
Hopefully, this blog post has given you a good estimate of how many calories are burned in infrared sauna sessions.
One study showed that you burn 600 kilocalories in an hour-long session (if you don’t take breaks) while the other showed ~500-1,100 being burned. These numbers are imperfect though, and more research on this topic is needed.
And yet, the amount of fat you can lose is surprisingly high if you regularly commit to sauna sessions.
Let’s put these numbers into perspective: if you weigh 80 kilograms (~12.6 stone) then you’re burning 700 kilocalories during an hour of mountain biking, 450 during ballroom dancing, 650 during a run on average speed, and 350 playing golf. Given the 500-1,100 kilocalories estimate I’ve arrived at during a 1-hour sauna session, it shows that the human body has to work very hard to counter the extreme heating from the inside out (assuming you’re using an infrared sauna).
Of course, many people won’t last for a full hour in an infrared sauna and doing so isn’t necessary for great health benefits either. As I always reiterate, more is not necessarily better. In the same way, most people cannot run at a speed of 10 miles per hour for an hour, the same is true for spending time in a sauna.
Be kind to yourself. Burning calories is a great benefit to spending time in the sauna but not the be all end all of the health benefits you’ll experience. I recommend reading my blog pots on the benefits and downsides of infrared saunas to develop a broader perspective of the benefits you’re likely to experience besides losing body fat.