Each of us has a unique rate at which we sweat. Many factors affect your sweat rate: body weight, fitness level, pace and intensity of activity, temperature, humidity, clothing, and hydration level. Taking inspiration from athletes in training, you can discover and manage your hydration levels and create a plan that helps you feel good about how much water you’re drinking. Athletes training hard drink an average of 400-600 ml (12-20 oz) two hours before intense exercise, or 5-7 ml/kg (16-20 oz/pound) of weight. Based on your own activity level and sweat rate, you can see how you might adjust your plan to fit your body and wellness goals.
Determining your baseline sweat rate for a specific activity is a simple formula:
Pre-activity weight - Post-activity weight + Ounces consumed during activity = Sweat rate
You can use this equation for any activity you do during the day and get an idea of how much water you need to replace the fluids you use when you’re exerting energy and sweating. For your sauna sessions, here’s how to use the equation:
- Weigh yourself without clothes right before you step into the sauna. The more exact weight you can measure the better – you need to know specific ounces.
- Enjoy your sauna session and write down the temperature, time, what you wore, and what you did (relax, stretch, yoga, meditate), and how much water you drank (or didn’t drink) during your session in ounces.
- Weigh yourself without clothes immediately after you step out of the sauna.
- Your weight loss is the measure of your sweat rate. (1 pound lost = 16 oz of fluid)
- If you drank water during your session, add in the number of ounces you consumed to the weight you lost.
- The resulting measure of ounces is your sweat rate for that activity and is a baseline for you to use going forward. You now have an idea of how much you want to hydrate to prepare for your session and rehydrate after.
Try a New Sweat Tracking Technology: Gx Sweat Patch
You may enjoy trying out a new tool just released this spring that makes measuring your sweat rate for an activity super easy and simple. It’s another way to get a benchmark idea of how much you sweat in a sauna session. Two companies recently collaborated to create a patch that measures sweat rate and sodium loss. It’s great information to have about your body to help you manage your water intake and electrolyte needs.
The Gx Sweat Patch comes in a package of two patches for $24 and connects to an app that tracks your bio data. You simply stick the patch on the inside of your forearm while you perform an activity and watch as it changes color. After you complete your activity, you scan the patch and the app translates what happened with your body into data: milliliters of fluid sweat out and amount of sodium lost (low, medium or high). The reason to watch sodium loss is to know if you need to replace electrolytes.
Either of these sweat rate calculation methods give you more information about your body to make customized decisions about how much to drink and whether you need to replace electrolytes or not. Once you have an idea of your sweat rate from either the weight method or sweat patch, the next step is to pay attention to how you feel over several sessions and drink more or less as needed.
The goal for optimal health is to make sure you do not lose more than 2-3% of your total body weight.
Keep in mind, the most recent research supports that thirst is the best guide for determining fluid intake; so always listen to your body and drink when you feel thirsty. Your sweat rate simply tells you how much fluid your body loses. In an earlier article, we explored how our bodies all have different “sweat fingerprints,” or unique make up of sweat pores. So naturally, this is why you may sweat more or less than someone else.
Barbara has a condition that makes regular exercise difficult, so she uses her sauna especially for its passive cardio benefits. She tracked her sweat rate during the Weight Loss program for 20 minutes:
Barbara’s Data Collection
- Barbara’s pre-sauna weight: 260 lbs
- Barbara’s post-sauna weight: 258.6 lbs
- She drank 8 ounces of water during the session
Barbara’s Calculation
- 260 – 258.6 = 1.4 lbs/22.4 ounces + 8 ounces consumed in session = 30.4 ounces sweat rate for her Weight Loss program session
Barbara’s Hydration Plan
- Knowing how much she sweat in the Weight Loss program session, she will plan to drink 32 ounces of water before she saunas so she knows she is well hydrated before she gets in.
James sweats a lot in his Amplify sauna. He is focused on living a healthy lifestyle and uses it every day to optimize his health in addition to eating clean and exercising. James calculated his sweat rate for a 30-minute session at 153 degrees:
James’ Data Collection
- James’ pre-sauna weight: 198 lbs
- James’ post-sauna weight: 197.4
- No water consumed during the session
James’ Calculation
- 198 – 197.4 = .6 lbs/9.6 oz. + 0 oz consumed in session = 9.6 oz sweat rate for that sauna session
James’ Hydration Plan
- With this data, Sam knows he needs to drink at least 9.6 ounces of water before his session, and after.
Emily is a runner and uses her sauna to keep her body healthy so she can keep doing what she loves and have a little “me time.” She tracked her sweat rate over five sessions using the Detox program and found she sweat an average of 8 ounces in that session, though it ranged from 3.2 to 11 ounces.
Emily’s Data Collection
- Emily’s pre-sauna weight: 134.5 lbs
- Emily’s post-sauna weight: 134 lbs
- No water consumed during session
Emily’s Calculation
- 134.5 – 134 = .5 lbs/8 ounces + 0 ounces consumed during session = 8 ounces sweat rate for that Detox program session
Emily’s Hydration Plan
- She’ll plan to drink 8 ounces of water before and after her next Detox program sauna session.
