Does Sauna Help Weight Loss?

Sauna benefits often sound too good to be true.  Regular sessions can decreases all-cause mortality, improve endurance, and does wonders for your skin.  But does sauna help weight loss?

As you’ll see, sauna can absolutely help with weight loss and promote a healthier lifestyle.  However, the weight you’ll loose in the sauna is mostly water weight that’s more of a short term win.

Sauna weight loss history

For decades, different types of athletes have utilized the sauna as a method to quickly lose weight for one simple reason: it works in the short term. But why does 30 minutes in the heat help with losing weight, and is sitting in the a sauna really a replacement for exercise? Does sweating burn calories? Do we never have to exercise again? If only….

It is technically true that there are calories burned in the sauna, and you will loose water weight for the simple reason that you are sweating like crazy in the sauna and your metabolic rate is high. But loosing weight is not a primary among the health benefits of sauna.

Finnish and Infrared Saunas will help you lose water weight, that water being sweating out in the sauna weighs something, and unless you’re replenishing it (as you should) you will temporarily loose significant weight in the sauna.

The health benefits of a sauna are significant and backed by studies, but to help you lose weight sitting in a sauna will provide only a temporary win. Losing water weight can be significant for certain athletic situations, but for most of us we should not use the dry or infrared sauna for weight loss, although the increased heart rate can achieve health benefits similar rigorous exercise .

Athletes and Water Weight

Professional jockeys, wrestlers, and those in mixed martial arts, taekwondo, Thai/kickboxing, judo, boxing, and Brazilian jiu-jitsu think nothing of sweating for long periods in the sauna, especially before weighing in for competitions.

MMA athletes have the highest sauna use to try to meet weight standards in the industry prior to competition.

But does sauna help weight loss in the long term?

What these athletes lose by sweating is fluids, not meaningful pounds from the burning of fat or calories burned. The fluid loss will soon be replaced when the athlete starts rehydrating. 

Using saunas and other rapid weight loss methods by wrestlers has not faired well in the medical literature. These methods have been linked to depression, decreased learning capability, renal problems and growth stunting. Doctors won’t ever recommend sauna weight loss; but nevertheless, it continues to be engaged in.

Yet, when you think about it, these athletes know something about how to lose weight. They might not know the specific answer to the question, how many calories do you burn in a sauna – studies are hard to come by on this topic – but they know how much fluid their own body will relinquish sitting in a sauna. 

By the way, some sauna companies answer the question, how many calories do you burn in a sauna on their site. They state it’s anywhere from 300 to 1000 calories for a 30 minute infrared sauna session. 

But think about it. 300 to 1000 calories still is a far cry from the 3500 calories that is needed to lose a pound of body fat. And it’s entirely possible that a supposed sauna weight loss session could be working against your efforts to lose weight. That’s because the process of breaking down fat depends on water. Without the water, you can’t break down the fat. 

How Much Weight Can You Lose in a Sauna?

An early study found that an average weight loss of 4% could be lost in an infrared sauna.  That means that if you weigh 150 pounds, you could drop six pounds in the sauna from fluid. 

This type of weight loss, which is rapid, was more detrimental to physical performance of athletes than weight loss achieved over a 48-hour period of time from exercise, the doctors in the study stated.

When one researcher studied three different methods: sauna, shower, and ice water immersion to see which method had the greatest weight loss, he tested the difference between heat and head-out ice water immersion, heat and 15 degrees Celsius shower, sauna and room temperature, and head-out ice water immersion and room temperature. 

Sure enough, he found a difference. The greatest weight loss was observed in the sauna and room temperature group. Thirty percent more grams of weight were lost when people used the sauna and then merely sat in a room at room temperature, compared to those who immersed themselves in ice water or took a cold shower after the heat. In this case, the weight loss was measured in grams, not pounds. The top weight loss was 544 grams. There are 453 grams in one pound. 

In 2003, a study at the University of Granada in Spain asked the same question how much weight can you lose in a sauna. He and his colleagues quantified how much weight was lost after three consecutive 20-minute sauna sessions at 70 degrees Celsius with a 5 minute rest interval in between. Here is one study where we actually get another important question answered – how long to stay in each session. 

They compared this to the weight of the volunteers after one hour of rehydration, offering 2.5ml/kg body weight every 15 minutes (about a cup of water every 15 minutes). The men lost 3.96 pounds and women lost 3.08 pounds. This amount of fluid loss could not be rapidly reversed through rehydration. 

Interestingly, the more water loss the women had from the sauna, the more they were unable to jump as high as they could before the sauna. Some women reduced their jump height up to 6% just because of poor hydration.

How Much Weight Loss Can Obese Patients Lose in a Sauna?

One Japanese study reported that in obese patients, the body weight and body fat decreased significantly after two weeks of sauna therapy. They didn’t report how much specifically so you will have to surmise here yourself on the number. Most likely it was in line with other researchers’ numbers, about 3-5%. 

In normal weight patients with appetite loss, repeated sauna therapy increased plasma ghrelin levels and daily caloric intake and improved feeding behavior. 

Why Does Sauna Help Weight Loss?

The bottom line is that you can expect weight loss from sauna sessions, but you really shouldn’t make it be your #1 way to lose weight. This is because too much fluid loss can lead to serious cases of dehydration and that leads to death. 

However, when using the sauna along with your other weight loss efforts, you’re going to create a win earlier than if you don’t slip in a few sauna treatments a week. 

That’s because of these reasons:

1. Sweating increases detoxification and flushes out heavy metals, chemicals and other impurities in your body. Once your cells are rid of these things, it’s easier for them to operate at full capacity and you will burn fat easier.
2. Saunas increase your body heat, and your heart rate and metabolism will rise in the sauna. This alone burns calories. It is thought that your metabolism will increase about 20% in a sauna. This is important for many people who have been on diets in the past that suppressed their metabolism. 
3. Saunas improve your ability to exercise by improving respiratory function, heart function, blood pressure, and the ability of your arteries to dilate.  You’ll feel like exercising and moving more – and do so, and this will burn calories.
4. Sauna sessions improve the functioning of your nervous system and take you out of fight or flight mode. When you’re in fight or flight mode, your cortisol levels are high, an you know what that means – belly fat!  But saunas stop the cortisol production. You’ll feel relaxed when you come out of a sauna session. There’s no way not to.

Best Saunas For Weight Loss

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Biro, S., et al. Clinical implications of thermal therapy in lifestyle-related diseases. Exp Biol Med (Maywood) 2003 Nov;228(10):1245-9. 

Caldwell, J.E., et al. Differential effects of sauna, diuretic- and exercise-induced hypohydration. J Appl Physiol Respir Environ Exerc Physiol 1984 Oct;57(4):1018-23.

Kauppinen, K. Sauna, shower, and ice water immersion. Physiological responses to brief exposures to heat, cool, and cold. Part I. Body fluid balance. Arctic Med Res 1989 Apr;48(2):55-63.

Weight reduction in wrestling. Phys Sportsmed 1981 Sep;9(9):78-96. 

Barley, O.R., et al. Weight loss strategies in combat sports and concerning habits in mixed martial arts. Int J Sports Physiol Perform 2018 Aug 1;13(7):933-939.