I’ve been going to the sauna regularly for almost 20 years, and since I’m a data junkie and a big fan of Garmin’s Fenix line of watches, wearing my watch in the sauna was a no-brainer. For those who are curious about my 6+ years of experience wearing my watch in the sauna, best practices, and reasons why I do it, here’s everything you need to know.

Disclaimer: I’m simply sharing my long-term experience here, and your mileage may vary. Although I’ve had no problems wearing my Fenix watches in the sauna, it’s important to note that Garmin doesn’t recommend this practice, which could void the warranty.

Can You Wear Garmin Fenix Watch in the Sauna?

What Does Garmin Say?

First, Garmin does not explicitly states that you can not wear your Fenix watch in the sauna or that it will automatically void the warranty. That being said, they do recommend removing your watch when entering the sauna, as it can expose your watch to temperatures outside of its operating specifications.

The phrase “temperatures outside of its operating specifications” is key, in my opinion.

Assuming you stay within the operating temperature range for your watch, you should be fine to wear it in the sauna. According to Garmin, the operating temperature range from Fenix 5 Plus up to the latest Fenix 7 is from -20°C to 45°C (from -4°F to 113°F). On the older Fenix 5, the range is even wider, from -20°C to 50°C (from -4°F to 122°F).

My 6+ Years of Experience Wearing Fenix Watches in the Sauna

If you are wondering – but wait, isn’t the air in the sauna much hotter than 45°C or 50°C (113°F or 122°F)?! Yes, in most saunas, it is. The saunas I visit have a temperature ranging from 90°C to 110°C (194°F to 230°F), but here is the catch: in order for the watch to stay within the operating temperature range, simply place a palm of your hand over it, and the temperature will likely not exceed more than 41°C. You can check for yourself by viewing the thermometer widget on your Fenix watch. In my experience, even an unprotected watch won’t exceed 50°C since your body is actively cooling it down.

My retired Fenix 5’s has endured hundreds of sauna visits (3-4 15 min. sauna sessions per visit) over the course of 5 years with no issues, and my current Fenix 7 also after a year and a half and around 70 sauna visits, also with no issues.

Does It Negatively Impact Battery Life?

No, at least not that I can tell. Depending on how much I’m running with GPS, I can still get around 6-10 days with my Fenix 5, which is pretty good considering its age. As for my Fenix 7, I can get about 14-19 days, but more importantly, the battery seems to me as good as new.

As I said earlier, if you make sure to keep your watch within its operating temperature range, you should be fine. From my experience, hiking on a sunny day can increase the temperature of the watch a lot more, especially if you use solar charging (for solar charging, Garmin allows temperatures up to 60°C/140 F°).

Why I Wear a Fenix Watch in the Sauna?

First and foremost, I’m a geek, so I don’t want to lose any data. If you take off your watch, you will lose heart rate and HRV-related data, which means your heart rate, stress, and body battery metrics will become less accurate.

Second, I like to measure the time of my sauna session. This is especially useful in public saunas where other visitors often use the sauna timer. The same goes for the cold plunge: being able to measure the time helps to stick to my cold exposure protocol (if this interests you, I highly recommend checking out Dr. Huberman on this topic).

As you may know, heat exposure can be a significant physiological stressor. Therefore, it can be a good idea to measure not only the time of each session but also your heart rate and training load with a dedicated activity profile created specifically for a sauna.

To do that, you can use the Other activity profile or create a duplicate of the Cardio activity on your Fenix watch, and label it as a sauna, but more on that in a second.

As you can tell from the screenshots, the training effect and the training load of the activity can be surprisingly high. If you go to the sauna twice a week, it can start noticeably impacting your acute training load. Therefore it might be a good idea to start measuring it.

Creating a Sauna Activity Profile

Since there isn’t a dedicated sauna activity profile on the Fenix watch, you will need to create one. I prefer to use the Other activity profile, as it fits my needs the best. However, there are a few different options available, each with its own advantages and disadvantages.

To help you choose the right activity profile for you, I’ve created a list of the top 3 activity profiles suitable for the sauna with their respective pros and cons.

• Other (Pro: allows for creating sauna workout, doesn’t clutter run activities, Con: less detailed stats)
• Cardio (Pro: looks clean in GC dashboard, Con: less detailed stats, not suitable for creating a sauna workout)
• Running (Pro: most detailed stats, allows for creating sauna workout, Con: clutters run activities)

Tip: If you are missing certain data in the Other or Cardio profile (such as Lap Avg HR, etc.), you can change the activity type to Running once uploaded to Garmin Connect, and the missing stats will appear.

Setting Up the Sauna Activity Profile

In this example, I will be using the Other profile, but the set up process is the same for any of the profiles listed above.

1. Press the Star/Stop button -> Scroll down to “+” -> Other -> Other -> Label the Activity as Sauna
2. Select Data Fields based on your preference. I like to use the 6-field layout with the following data fields:
   – Training Effect Gauge,
   – Timer, Lap Time
   – Temperature, Average HR
   – Heart Rate Gauge
3. Satellites setting set to Off (if you’re using the Run profile, I would turn off the Running Power as well),
4. Record Temperature set to On. Done!

Creating a Sauna Workout

I also like creating a “sauna workout” to track each step of my bathing routine (sauna session, cold plunge, and rest). This allows me to keep track of my sessions.

To do that, you will need to go into Garmin Connect and tap the “••• More” where you’ll find the Training & Planning menu -> Workouts -> Create a Workout -> Choose Custom (or other profile based on what you’ve used to create your Sauna profile).

Here I like to create 4 repeats (since I usually do 4 sauna sessions during a visit) of a 3 step “sauna workout” (sauna session, cold plunge, and rest). I prefer to initiate each step with a Lap button press, but you can also automatically start each step based on time or heart rate.

That’s it! Now all that is left to do is to sync up the workout to your watch, load it up in the activity profile, and hit the sauna!

Happy sweating! 🙂