Amazing news—you’ve just joined a new gym, and it has a sauna! Or maybe you’ve been walking past it for months, never sure exactly how you’re supposed to use it. Do you need to wear clothes? Are you supposed to do it before or after your workout? Can you bring your phone with you? 

The answers to these questions may vary from gym to gym, but I’m going to do my best to provide useful advice and pointers anyway. To be clear, I’m talking about the saunas that are found in gyms and in swimming pool complexes in the U.S., and how people typically use them. This is not a guide to, say, Finnish sauna traditions—just a survival guide for checking out the sauna at your local YMCA or Crunch.

What are the benefits of using a sauna?

Wondering why people are in the sauna in the first place? There are a variety of reasons—some traditional, some science-based, and some based on how the sauna makes you feel. 

Many people use a gym sauna for the recovery benefits. The evidence isn’t super conclusive, but several small studies have found reduced muscle soreness after using a sauna, and some have found that people seem to recover performance (like jump height) more quickly after a workout if they used a sauna. To give a few examples: this study found a benefit to recovery in basketball players; this one found an improvement in endurance performance among runners; and this one found that sauna use made swimmers perform slightly worse the next day. If you’re interested in using the sauna for recovery, try it out, and see how it affects you. 

Sauna bathing (as it’s sometimes called) may have cardiovascular benefits that mirror some (not all) of the benefits of exercise. Your blood vessels dilate in their futile attempt to cool you off, and this seems to be good for cell growth and repair, keeping your circulatory system healthy.

Does a sauna help you lose weight? 

Not really—except in the sense that you sweat while you’re in the sauna, and that dehydrates you a bit. The water you lose by sweating does have some weight to it, so you might leave the sauna a pound lighter than you entered. The weight you “lost” was all water, though, and will be replaced as soon as you have your next beverage. 

This is why you’ll see wrestlers and other weight-class athletes hitting the sauna before a competition: It helps them temporarily lose weight so they can hit a specific number on the scale—and you can bet they’ll rehydrate as soon as they make weight.

In terms of fat loss, which you’re probably asking about: nope. Not at all. Sweat is just your body cooling off. It is not a sign of a good workout or a sign that you are burning calories. A session in the sauna does absolutely nothing to further your long-term weight loss goals.

If you wear a fitness tracker into the sauna, you may see a high heart rate and even (if you attempt to log it as a workout) a high calorie burn. This is a mathematical illusion—your fitness tracker knows that the higher your heart rate during exercise, the higher your calorie burn. But if something other than exercise raises your heart rate—something like sitting in a sauna—the relationship no longer applies. Sorry, you are not burning tons of calories just sitting there. 

Are there different kinds of saunas? What kind does my gym have? 

Your first step is reading the posted rules (and any other signage) and taking a quick look around. You can do this during the gym tour, or the next time you’re in the locker room. If you poke your head into the sauna itself to take a look, make sure not to open the door wide or hold it open—try to keep the heat inside. 

A few things you may notice: 

A sauna is dry; a steam room is wet. We’re talking about saunas today, but some places have both. 

Regular saunas have benches, can fit several people, and have a stove or heater that heats the air in the whole room. Infrared saunas are more likely to be single-person booths, and they use infrared lamps that heat your body without necessarily making the air feel very hot. 

Can you pour water on the rocks? In traditional Finnish-style saunas, there are rocks on top of the stove that you can ladle water onto for a burst of steam. Most gym saunas use an electric heater that you should not pour water onto. There’s often a sign, “NO POURING WATER ON THE ROCKS.” (If you are allowed to pour water onto the rocks, you should still ask the other people in the sauna if they are okay with you doing it. Not everybody wants the steam, and it’s rude not to ask.)

The posted rules will also answer some of the other questions you might have, so start there if there’s something you aren’t sure about. That said, there are plenty of different ways people use saunas, so let’s get into the rules of etiquette you can expect to see followed.

What do I wear? 

In many sauna traditions, you’re expected to be naked, but in your average commercial gym, it’s a lot less common to see people stripped all the way down—and the rules might prohibit nudity, anyway.

If the sauna is in a swimming pool area, it will be pretty normal to wear a swimsuit into the sauna. You might even see people coming out of the sauna to take a cold dip in the pool, then repeating the process. 

As a general rule, if the sauna is in a public or mixed-sex area, like on the pool deck, a swimsuit or some other body covering is expected (versus going in naked or in just a towel). If the sauna is located in a locker room, though, that’s considered a more private place. I was recently in a Crunch Fitness where the locker room sauna rules stated simply: “No street clothes, but please wear a towel.” 

Over a few days visiting that Crunch, I noticed one person who used the sauna in just a towel, and six people who went in there in their gym clothes, including shoes (??!?) and with their phone. We’ll talk about electronics in a minute, but I just want to say: while this may be common in some places, and so you’ll have to get used to seeing it, I wouldn’t recommend it as a good way to use the sauna. 

To summarize:

The most “normal” thing to wear in a sauna is a towel.

If you’re going in naked, bring a towel to sit on.

Swimsuits are usually fine to wear, and may be required.

Gym clothes (and sometimes even shoes!) are often allowed in gym saunas, but I wouldn’t recommend going in fully dressed unless you’re doing a super quick warmup before your workout.

Do I use the sauna before or after my workout, or on its own? 

You actually have a lot of different options. There isn’t one Truly Right and Correct time to use the sauna. Take your pick. 

After your workout (or swim) is the most common time to use the sauna, and it can fulfill a variety of purposes. One is heat adaptation: if I’ve been running on the treadmill in the air conditioning because it’s a million degrees out, I’ll do a sauna session afterward to help my body stay acclimated to the heat

More often, the sauna is used after a workout for relaxation, cardiovascular benefits, and/or recovery. As mentioned above, some research suggests that using the sauna after your workout can help you recover better for future workouts. 

So the most common way to use the sauna is to finish your workout, peel off your clothes, and optionally take a quick rinse-off shower before hopping into the sauna (some gyms’ rules require the shower, although honestly I don’t see the point—you’re going to sweat anyway). 

Before your workout: this isn’t the time for a full sauna session, but spending a few minutes in the sauna can provide a passive warmup—literally warming you up before you start to exercise. If it’s a cold morning and you’re feeling stiff, go ahead and spend five minutes or so in the sauna before starting your workout.

After your workout: this is when most people will use the sauna, and it’s up to you how long you’d like to spend in there.

On your rest days: People are always asking “Is it weird to go to the gym just to use the sauna?” No! It is not—that’s one of the nicest perks of going to a gym that has a sauna. Go on your rest day and treat yourself.

How long should I stay in the sauna? 

Your first time in the sauna, you probably won’t want to be in there very long. Five or 10 minutes is fine your first time. A longer session is more likely to be 15 to 30 minutes. I wouldn’t recommend staying in longer than that. 

Don’t forget that you can come out to cool down, and then go back in. In some sauna traditions, this is the whole point: heat up, cool down, repeat for maybe three rounds or so. But it’s also okay to just do the length of time you’d like, and then call it quits for the day. 

Can I bring my phone in the sauna? 

Look, people do. That doesn’t mean you should. The heat of a sauna is not kind to electronics, so most manufacturers warn against bringing your gadgets in. Apple, for example, notes that ambient temperatures over 95 degrees “can permanently damage battery capacity” in the iPhone and Apple Watch (saunas are usually somewhere between 150 and 200 degrees), and that using your phone in a sauna or steam room can increase the risk of liquid damage.

Most other electronic devices will carry similar warnings if you look up their recommendations. So your headphones, smartwatch, and phone should be left in your locker. The one exception I’ve found? The Oura ring. It’s made by a Finnish company. Of course you can wear it in the sauna

If you’d like to time your sauna sessions without risking damage to your expensive electronics, consider swapping your smartwatch for a basic digital watch like this Casio. (Armitron also makes some good basic watches, like this one.) 

So what do I do in there? 

The answer to this question depends a bit on the vibe at your gym. If you’re there with friends or if your gym is a chatty community, people might talk and socialize. But more commonly, everybody sits there and does their best to stay silent and avoid eye contact. (It’s not like talking is prohibited, but please don’t go out of your way to start a conversation.)

The sauna is often a place for people to relax, so consider closing your eyes and letting your mind wander—or meditating, if that’s your thing. 

Above all, it’s a small, shared space, so be polite. Sauna etiquette decrees: Don’t shave or trim your nails. Don’t watch videos with the sound on, or otherwise make annoying noises. Don’t do yoga, or spread out your stinky gym clothes to dry, and definitely don’t drizzle essential oils on the heater (yes, I have heard of people doing all of these things). And definitely don’t stand in the doorway letting all the heat out.

All that said—if you’re the only one in there, most of the above doesn’t really matter. Just leave the place the way you found it, and act normal if somebody else walks in.

Should I cool off afterward?

After you leave the sauna, you’ll want to take some time to cool off. The air outside the sauna will feel refreshingly cool, but you’ll want to make your way toward the shower. 

Take your time cooling down. Sauna time is over, and you want to bring your body temperature back down to normal. If you hop out of the sauna right into a super quick shower, you may find yourself continuing to sweat through your clothes after you get dressed. 

What should I bring with me to use the sauna? 

Here’s your starter kit for a satisfying sauna session: 

A lock for your locker, so you can leave your phone and valuables in there (don’t bring them in the sauna)

A dumbwatch, if you’d like to time your session

Two towels: one to wear in the sauna, and a fresh one for after your shower (I like packable microfiber gym towels that won’t take up much space in my gym bag)

Toiletries to shower afterward