Can Saunas Help You Cut Fat?

Traditionally, saunas have been used as a way of socializing, relaxing and recovering. They help you to sweat your worries away, de-stress and take a bit of time for yourself.

They might not be as popular in the US as they are in places like Scandinavia, but you’ll still find them in various gyms and health centers.

The question is though; could you relax, get a good sweat on and also burn fat at the same time?

In this article we take a look.

Here’s what we’ll cover:

  • What is a sauna?
  • Could heat exposure help you lose weight and burn fat?
  • What are the health and performance benefits of heat exposure?

What is a Sauna?

A sauna is an enclosed room that gives the user an experience of either dry or wet heat. They are usually decorated for comfort, with wooden panelled walls and comfortable seating. All you need to do is strip down to your towel or beachwear and relax.

Traditional saunas use wooden stoves or heaters to heat the air to around 85°C [1]. In both cases you’ll experience high temperatures and low humidity.

Sometimes you’ll come across infared heated rooms that run at a slightly lower temperature, but use light waves to affect the body instead. These aren’t nearly as warm but are said to provide similar benefits.

Typically, you’ll spend only 15-30 minutes in a hot sauna in order to get the benefits, without exposing yourself to excessive dehydration.

Health benefits

Regular sauna use can help boost circulation, improve blood pressure and reduce the risk of heart failure. They promote relaxation and vigor, and are a great way to relieve stress. They can also boost your immune system too.

Heat exposure can help your muscles relax after a tough workout and sooth aches, pains and joint discomfort. And whilst ‘flushing toxins out of the body’ is a bit of a misleading term, heat exposure does help to open your pores and remove impurities from the skin.

But could they help you strip fat and improve body composition?

Let’s find out…

Can You Burn Extra Calories in a Sauna?

Saunas are well known for their ability to make you sweat. Why? Well because they are hot. Very hot.

And when your body is presented with such heat, it triggers changes referred to as thermoregulatory homeostatic responses. These include sweating, dilation of your blood vessels, increased heart rate and increased blood flow. and are all initiated in order to help you body keep as cool as possible.

It is claimed that these homeostatic effects give your body a similar response to that of walking at a moderate pace [1]. 

So saunas could help you lose weight?

Technically yes, but don’t get too excited yet though.

Saunas have been used as rapid weight loss tools by athletes for years. For example, when jockey’s want to hit their target weight, many of them use saunas [2]. Likewise, they are used by a number of other weight class event athletes too. It’s a common approach in weightlifters, boxers, rowers and martial artists.

So why do they do this?

Well, because saunas dehydrate you very quickly.

This means that you lose weight from the water that you are sweating out. In fact, research shows that some athletes lose as much as 4% of their body weight using this method [3].

That’s good though right?

No. For a few reasons. Firstly, it can negatively affect your mood, health and performance. It can cause decreases in power and endurance and it can cause dehydration illness too. Lose much more than 5% weight through fluid loss and you’ll end up seriously ill.

And if do lose weight, what do you think will happen once you have a drink after your session? That’s right. You’ll just store the lost water and your weight will go back to what it was before.

The reason why athletes use saunas in this context is purely so they can achieve a given weight. Once they’ve done this at their weigh-in they’ll drink and eat and get their weight back up to what it was before.

Key Point: Saunas can help you lose weight, but all you’re losing is water. Whilst this can cause you to lose weight rapidly, it isn’t a sustainable or safe way of doing it.

Can You Burn Fat in a Sauna?

As we’ve seen already, heat exposure will very likely help you lose water weight. But are there any benefits to fat loss or is it all a waste of time?

It is commonly thought that saunas help to boost your metabolic rate by potentially up to 20% through a process called thermogenesis.

And whilst it might only be a modest amount of calories in this case, saunas may indeed contribute towards fat loss. We say contribute because using a hot room to boost metabolic rate will have a modest effect on its own.

But couple it with a productive diet plan, regular exercise and some good supplements and you’re well on your way.

Thermogenics such as green tea and red chilli have been found to make big differences to body composition and fat loss, but in reality, any differences a sauna will make to body composition will be minimal at best. Without a full lifestyle approach they are unlikely to make that big a difference.

In fact, saunas have such a modest effect on fat loss that one review suggested that rather than sauna use, fat loss should be encouraged by [4]:

  • Hitting a negative energy balance
  • Avoiding high fat diets
  • Strength and conditioning training to maintain muscle mass
  • Focus on a nutrient-rich diet

Performance Benefits of Saunas

Whilst long periods in the sauna might not be a good idea, safe sauna use might actually help to improve your athletic performance.

Saunas could help you build muscle

In order to build muscle you need to create cellular damage. By doing so your body responds by growing muscle fibers back that are bigger and stronger. This is called the ‘tear and repair’ process.

Both weight training and saunas have been found to elevate levels of a specific protein called heat shock proteins (HSPs). You’ll find these in a number of different types of cells, but more importantly you’ll find them in muscle cells.

When elevated, HSPs aid in muscle protein synthesis – they speed up the muscle repair process by encouraging cellular repair. This means more muscle tissue and bigger muscles. 

A study by Leppaluoto et al [5] found that when volunteers were given twice-daily, hour long sauna sessions over a one-week period, growth hormone levels increased 16-fold within the first three days. And growth hormone plays a big role in muscle protein synthesis too.

How do you use this information to maximize results?

Easy. Lift some weights then go and have a sauna. Let your hormones do the rest.

Heat exposure improves endurance

A study published in the Journal of Science and Medicine in Sport [6] found that a 30-minute sauna session only twice a week could improve running to exhaustion by 32%. Why? Because red cells count increased by just under 4% and blood plasma by 7%. Because both of these factors help to increase the amount of oxygen delivered to the muscles.

It does this by accelerating the production of erythropoietin (EPO) –  a hormone released from the kidneys that increases the rate of production of red blood cells in response to a decrease in oxygen in the blood and muscles.

So if you’re a runner, cyclist or any other endurance athlete, this is a big bonus.

Key Point: Saunas can elevate both growth hormone and heat shock protein levels. Both are important muscle building hormones.


Saunas are a great way to relax. They help recovery from a tough workout, and are great just to socialize with friends. And whilst they can contribute to short term weight loss due to dehydration, they won’t help you burn much fat.

But that doesn’t mean that they’re not beneficial.

Spending just 30 minutes a couple of times a week exposing yourself to heat can help improve your endurance, muscle mass and aesthetics. Just make sure you keep yourself hydrated and only use them once you’ve been cleared by your medical professional.