Can You Lose Weight in a Sauna? An Easy Guide!

Medically reviewed by Dr. Justin Ternes
As an Amazon Associate we earn from qualifying purchases made on our website.

Saunas are great for de-stressing and detoxification. All that heat and sweat helps the body relax and push out toxins. But when it comes to other benefits like weight loss, does a sauna really help? There is a lot of debate around this topic, and plenty of people are giving definitive answers. Can saunas really help you lose weight?

You do lose weight in a sauna, both from water loss (sweat) and from burning more calories with an increased metabolic rate. A 30-40 minute sauna session can easily shed more than a whole pound of water weight, with an added 200-300 extra calories burned.

You might not think that a sauna can benefit your weight loss, but there are a surprising amount of calories burned during sauna use. While it might not be a substitute for exercise and dieting, sauna sessions can be an essential part of your weight loss plan. Not only are they a great compliment to a workout, but they also have other benefits. If you want to learn more about saunas and weight loss, read on!

Does a Sauna Actually Burn Calories?

Woman sitting in a sauna meditating

When we talk about saunas burning calories, people often assume sweat equals weight loss. But this isn’t quite the truth. There is quite a lot going on physiologically in our bodies when we are in the middle of a sauna session. Sweat is just the response to our body trying to regulate its heat.

Although there are several different types of saunas (more in our guide here), using any of them can lead to weight loss and calorie burn. Regardless of the style of sauna, your body is experiencing an abnormal amount of heat. In an effort to cool things down, your heart is pumping blood toward your skin to activate the sweat glands. This extra exertion will burn more calories than just sitting down, but not by as much as we’d like to think.

While your heart is pumping harder to help cool you down, it certainly isn’t working as hard as it would if you were, say, playing basketball. But you might get a similar amount of sweat, so what gives? Again, sweat is a physiological reaction to excessive heat.

In the case of exercise, it is managing heat created from muscle movement. In the case of the sauna, the external environment. While they seem like a similar reaction, they don’t equate to the same number of calories burned.

So when it comes to calories, a sauna does help burn them, but all that sweat gives you a skewed picture. This often leads to some misinformation about weight loss in saunas. All that sweat is burning calories, but most of the weight you lose will come back when you rehydrate after your session. But they do burn fat, and can have some surprising effects.

Do Saunas Help Burn Fat?

There are a couple of interesting aspects of sauna use that contribute to weight loss. While sweating isn’t indicative of losing fat, per se, the sweating is coming with several other effects in your body. 

When your heart is pumping and your blood is flowing, you’re burning calories. When you enter a sauna, you boost your heart rate, so, you increase your calorie burn. While most of the weight you see coming off is water weight, there is no doubt that some fat burns as well, but maybe not quite as much as it seems.

Another factor to consider is the role of cortisol in your body. Cortisol is a stress hormone that your body releases. Researchers believe it plays a part in how your body retains fat. Consistent sauna use can help you regulate this hormone. This results in your body being better at calorie management and overeating as well as de-stressing effects.

The next thing we should examine is metabolism. When your body is in the sauna, metabolism boosts to around 20%. With regular use, this can have an effect on the rest of your day.

This means that even after the session is over, you’re still reaping the benefits of increased metabolism. This is known as the afterburn, and it can help you tackle stubborn fat deposits like underarm and belly fat especially. We have a larger review of how sauna use addresses belly fat, so if that’s a priority for you be sure to check it out.

How Many Calories Can Sauna Use Burn?

On average, your resting metabolic rate will increase 1.5x to 2.0x in a sauna. So, whatever your resting calorie burn rate is, it will be increased by around this much for the duration you’re in the sauna. For a 50-minute sauna session, this can easily be an extra 300 calories even if you’re only working up a light sweat.

This figure will vary from person to person, and especially from gender to gender since females typically have a much lower resting metabolic rate than men. However, you can figure up a better estimate based on your unique situation by following the steps below.

  • Find your base metabolic rate (BMR); this will let you know, on average, how many calories you burn in a day.
  • Take your BMR and divide it by 48. This will give you a general idea of how many calories you burn in 30 minutes while in a resting position.
  • Now, with your divided BMR, multiply it by 1.5 — Divided BMR x 1.5 = Calories burned.

So, for example, let’s say you are a 180 lbs young man that is 6 feet tall. In this scenario, your BMR would be 1,824. Now, 1,824 divided by 48 is 38. So in a sauna, based on our equation,  this hypothetical person burns 57 calories in a 30-minute session. To give you a relative marker, if you ran that same amount of time, you’d burn around 420 calories.

There are some huge caveats here. The first being we are all different. The way I burn fat and calories is vastly different from your body. Age, weight, height, metabolism rate, family history, and health all play a factor in determining caloric burn.

Moreover, environmental factors in your sauna also come into play. How hot your sauna is, whether it is dry or steamy, and, session times all factor in. Generally speaking, though, you can expect to burn anywhere from 40-70 calories per 30-minute session.

Do you Lose Weight in a Sauna?

When you use a sauna, you definitely lose weight. Some of it will be water weight from all the sweating, while a smaller amount will be from the increase in your metabolic rate.

When you exit your sauna and weigh yourself, you might be delighted by the results. You need to keep in mind that this is mostly water weight excreted through sweating. Around 60% of your body is water weight. We have a whole article about how saunas can easily dehydrate you, so be sure to replenish at least some of this weight quickly after your session!

Sweating to lose weight has a long history in fighting circles. Athletes will try and cut weight before a weigh-in using all kinds of tactics, sauna sessions being one of them. But once you rehydrate after your session, the weight will come right back. So, how much water does a sauna remove?

How Much Water Weight Does Sauna Use Remove?

When it comes to the exact amount of water weight you lose, it’s going to depend on a few factors. One study conducted in 2014 found that, on average, a healthy person loses around 0.5 Kg (1.1lbs) of body mass during a 15-minute sauna session. The study also concluded that people with higher BMI tend to lose less body mass in the sauna relative to individuals with a healthy weight.

Researchers found that for individuals with a higher BMI, they reached dehydration quicker. This means they were burning water weight before fats.

This weight loss is more than just water. It’s also minerals, basic sugars, and different types of fats. Once the water and other compounds are replenished, there is still a decrease in body mass loss (BML). Researchers found that there was a correlation between BMI, BML, and sauna use.

Leave a Comment