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Sweat Rate Worksheet2019-01-23T22:04:05+00:00

Sweat Rate Worksheet


This worksheet should not be used as a replacement for health recommendations made by your health care team but can serve as a guide to help you better understand your specific hydration needs. Sweat rate is the amount of fluid you lose during one hour of exercise through sweat. The amount of fluid you consume during one hour of exercise should equal your sweat rate. Your sweat rate will increase in hot and/or humid weather and it is a good idea to complete this worksheet every time the seasons change or your climate changes. To measure your sweat rate you will first weigh yourself before you exercise, perform your exercise session, then weigh yourself after exercise to determine how much weight you lost during your workout. You will need to take into consideration how much fluid you drank during your exercise session and your urine volume during exercise, if applicable. Follow these tips when measuring your sweat rate:
  1. Go to the restroom before you weigh yourself at the start of your workout (box A). The process is much easier if you don’t use the restroom during your exercise session, but if you do, record the urine volume excreted during exercise (box C).
  2. Measure the amount of fluid (in ounces) in your water bottle before you begin exercising.
  3. Weigh and exercise in the least amount of clothes as possible. Sweat will absorb into clothing and could affect the accuracy of the formula.
  4. Do not remove or add clothing during the exercise session. As soon as your exercise session is complete, weigh yourself again (box D).
  5. Measure the fluid left in your water bottle at the end of your exercise session and subtract from the beginning amount to determine how much you drank (box B).
  6. Record exercise time (E).
  7. Record date, humidity percentage and weather temperature for reference when comparing multiple sweat rates.
  8. Use the formula to determine your sweat rate (box F).
  9. You can record four sweat rates on this worksheet, perfect for tracking seasonal changes.
  10. A loss of 1 gram of sodium per liter of sweat is assumed (1 liter = 33.81 oz). Use this information to customize sodium needs during and after exercise.

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Use the tips and complete the worksheet below using the formula to determine sweat rate.

Humidity %
A Body Weight Before Exercise (record in pounds)
B Fluid consumed during exercise, (record in ounces*)
C Urine volume excreted during exercise (record in ounces)
D Body weight after exercise
E Exercise time recorded in hours
F Sweat rate

* 1 cup = 8 ounces. 1 gulp is estimated at 1 oz.

Complete this formula to determine sweat rate:

  1. A-D = change in body weight recorded in ounces (1 pound = 16 ounces) = _____________
  2. Change in body weight + B – C = Sweat Volume = ____________
  3. Sweat Volume divided by Exercise Time (E) recorded in hours (30 minutes = .50 hrs.) = ___________. This is your sweat rate (box F) and the number of ounces of fluid you should consume during one hour of exercise.