Staying hydrated during a workout is important for your health and workout performance. How much water you need when working out at the gym depends on the time spent exercising, your sweat rate, and how your body absorbs and loses fluids. To know if you’re properly hydrating during a workout, you need to determine your sweat rate.
An individual’s sweat rate is the amount of fluid lost during exercise. Sweat rate varies based on the individual, activity, and the environment in which it’s performed. An advantage of working out in the gym, in a controlled temperature environment, is your sweat rate, once calculated, should remain about the same for each workout.
Starting with an empty bladder, weigh yourself pre-workout. Post-workout, weigh yourself again. Then, follow the simple calculations below to determine your sweat rate, and the amount of water you should consume per hour of a workout. With this information you should pace your drinking water at the gym accordingly.
Sweat Rate Calculation
Calculation | Example |
Pre-exercise weight – Post-exercise weight = Weight lost | 140 lbs – 138 lbs = 2 lbs |
Weight lost x 16 oz. = Oz. lost during exercise | 2 x 16 = 32 oz. |
Oz. lost during exercise + Oz. consumed during exercise = Total Oz. used during activity | 32 + 14 = 46 oz. |
Total fluids used during exercise/ Hours of exercise = Sweat rate | 46/2 = 23 oz. per hour |
Pace Your Water Intake
If your sweat rate results in a water consumption number that is a little daunting to you, determine a good way to pace yourself drinking water at the gym for the duration of your workout.
Drinking water at the gym every 10-20 minutes is a helpful guide to avoid dehydration during a workout. Using the example above, if you need to consume 23 oz. of water per hour working out, you can drink a little less than 8 oz. every 20 minutes or a little less than 4 ounces every 10 minutes.
While knowing your sweat rate is a great guide for drinking water at the gym during a workout, you know your body best. If you find yourself feeling thirsty or dizzy, or you feel a headache coming on during your workout, it’s likely you’re already dehydrated. You should focus on rehydrating regardless of time intervals.
In summary, determining your sweat rate is a helpful calculation to understand the basics of your body and its needs during exercise. Knowing your sweat rate, and drinking water at the gym according to your body’s needs, will serve your body and workout well.