April 14, 2022
13 MIN

How to Calculate Your Sweat Rate

How to Calculate Your Sweat Rate

Here is a quick guide to help you figure out how much water to drink while running.

1. Weigh yourself nude

2. Run for an hour

3. Measure the amount you drink during an hour run

4. Weigh yourself nude after your run

5. Subtract the after run weight from the pre run weight.

6. Add amount you drank to that number

7. The total is your sweat rate for the hour run.

Example: 120 lb at start

                -118 lb at end

                      2 lb loss… then add amount of water drunk during run

                    + 14 oz

Total sweat rate loss is 2 pounds 14 oz… or 50 ounces.

You can then divide 50 ounces by 4 and this will tell you how much to drink every 15 minutes. 

Weather conditions vary day to day. It is important to repeat the test a few times to get a clearer picture of how much you sweat and need to replace. The idea is to replace sweat as you lose it.

Studies have found that dehydration of two percent of bodyweight leads to about a six percent reduction in running performance.

Symptoms of Dehydration

o Feeling thirsty, which means you’re already dehydrated! Yikes.

o Fatigue

o Dry eyes and or/dry mouth

o Cramps

o GI distress

o Headache

o Confusion

o Muscle spasms

o The feeling that exercise is much harder than it usually is

o Lethargy