How to Stay Hydrated Before, During, and After Your Sauna

There’s nothing like the invigoration you feel after a sauna – but there is a caution. You have to stay hydrated during the process. The process includes being hydrated before, during and after your sauna. 

Dehydration isn’t a good thing to experience, and it’s life threatening. Luckily, there haven’t been very many deaths due to dehydration from saunas over the years, but there have been some naïve people who made some not-so-wise decisions and ended up meeting their Maker as a result. 

Sauna Deaths Not Usually from Dehydration 

One of these types of dumb decisions is drinking alcohol before or during their sauna experience. The alcohol clouded their judgment, interfering with executive functions of the brain. This means they couldn’t make rational decisions – and continued drinking while in the sauna. Their judgment may have been impaired for their ability to move, and some ended up falling on the hot coals of the Finnish sauna or Native American Indian sauna, and dying as a result of the burns.

Alcohol is also dehydrating, and during a sauna, you can lose even 2 to 3 pounds of fluid without the alcohol. So imagine how the alcohol compounds the water loss and could easily lead to dehydration. Of course, one of the signs of dehydration is confusion – and lack of even more executive functions of the brain – and more dumb decisions are easily made. 

How to Stay Hydrated – What To Know 

Staying hydrated is always a challenge for many people, but it doesn’t have to be. Below are some facts about hydration, and how to stay hydrated before your sauna experience:


How Much Water Do You Normally Drink To Be Hydrated?

To be hydrated, you have to drink enough fluid. Your fluid needs are easily calculated. Simply take your body weight in pounds and divide by two. This number gives you the total number of ounces of fluid you should drink in a normal day. 

For example, if you weigh 160 pounds, 160/2 = 80 ounces per day. Eighty ounces divided by 8 ounces in a cup = 10 cups water per day. If a water bottle contains 16 ounces, this would equal 5 water bottles per day. That’s for normal fluid consumption.


Counting Other Fluids is Allowed BUT…

Now if you want to get technical, you can always count even coffee and juice and milk as part of your fluid consumption. 

If you want to be super-technical and you eat 3 cups of watermelon in a day, there’s even a significant amount of water there in that watermelon that you can count towards your fluid consumption. 

However, most people don’t count these extra amounts of fluid intake unless their body mass is so great that it’s impossible to consume 12 or 15 bottles of water daily. 


It’s Easy Math Calculation Time!

Now knowing that you can lose up to 2-3 pounds of water in one sauna experience, you can see that prior to getting into the infrared sauna, Finnish sauna, or whatever type of sauna you’re using, you’ll have to prepare. 

One pound of water is equal to about 2 cups of water. This means you’re going to have to make up 6 cups of water from the sauna session. Making it up after the sauna is a bit too difficult for most people, so why not get hydrated before your sauna session? 

You can easily drink two bottles of water (1 bottle = 2 cups water) prior to the sauna if you’re like most people. Then during your session, you can drink another bottle. This way you are staying ahead of the dehydration that could result in the sauna.


No Time to Drink Fluid Before the Sauna?

Let’s say you’re involved in a ‘running ragged’ schedule and you just can’t get in those two bottles of water before the sauna. Your alternative option is to drink them both in the sauna, and then drink two more once you come out of the sauna. You’ll have to make a concerted effort to do this. 

Consider it sauna wisdom to calculate your water intake to prevent dehydration in the sauna and remain hydrated.

What Do Studies Say About Hydration in the Sauna – and Dehydration?

In Melbourne, Australia, researchers at the School of Health & Biomedical Sciences at RMIT University surveyed 572 regular sauna bathers about their sauna bathing habits. They knew that saunas are gaining a lot of popularity amongst those who really are concerned about their health. Sauna therapy is also known as whole body thermotherapy amongst the Aussies. 

The sauna bathers were split almost equally between men and women, 51.3% men and 48.7% women. They were predominantly well educated (almost 82%) and sauna bathed one to two times a week. 

You should know that the key reasons why they were sauna bathing were for relaxation and to reduce stress, relieve pain, and socialize. Nearly one-third of them had medical conditions, primarily back and pain in their muscles and bones, as well as mental conditions. 

Eighty-three and a half percent reported they slept better after their sauna sessions. But one thing that came up on this survey was that 93.1% of them did report symptoms of dizziness, dehydration, and headache. These weren’t bad enough to check into a hospital but they were nevertheless reported. It shows us that even regular sauna bathers have to still be careful about hydration before, during and after sauna use. 

The Real Details about Dehydration in the Sauna

Some studies get pretty technical about dehydration and provide us with some incredible facts and sauna wisdom. Here are a few of them:


If you lose 2% of your body weight in sweat, you will reduce your aerobic power by 20%.

Here are some charts to help you see what this really means:

chart showing how to stay hydrated throughout a sauna session


If you lose 2.5% of your body weight in sweat, you will reduce your aerobic power by 30%.

Wow, look at these numbers, and imagine how some wrestlers and other types of athletes could really be interfering with their performance if they don’t stay hydrated:

sauna hydration chart


Significant dehydration is 5% body water loss.

It reduces sweating threshold. Surprisingly, researchers at the Exercise Physiology Laboratory at Southern Illinois University found no difference in isometric strength and endurance when 4% of the volunteers’ body mass was lost from sweat loss in the sauna 3-1/2 hours prior. However, this doesn’t mean you’re free and clear to lose 4% body weight in sweat in the sauna and not have to worry about dehydration. 

This amounts to these numbers:

how much water to drink before a sauna


Body water loss greater than 8-10% leads to death. Here’s a chart that you should know about:

sauna water consumption


How to Know for Sure You’re Not Going to Get Dehydrated in a Sauna

Matching fluid consumption with sweat loss will minimize dehydration, according to researchers in Poland. Thus, it’s important to get on a scale before and after the sauna to estimate how much body fluids you lost should be replenished. 


Carbs Keep Water in Your Body

Carbohydrate holds water in the body, so if you are on a keto diet, water loss in the sauna could conceivably be more difficult to replace. Thus, you’ll have to make even more efforts to rehydrate than those not on a keto diet.

Don’t let a fear of dehydration prevent you from going into the sauna. Now you have all the answers. 

An finally, certain teas can actually help you stay hydrated and loose weight.  Check out the best slimming teas that help with hydration, weight loss and detox (depending on the tea, of course!).