Hydration Planner

Turn a measured Sweat Test into a practical fluid strategy for training and race day.

Measure first. Plan second.

EnduroPace begins with a measured Sweat Test rather than assuming that every athlete loses fluid at the same rate.

The Hydration Planner then combines your measured sweat rate, expected duration, and selected Fluid Replacement percentage to build an hourly target and a simple drinking schedule.

Measured Sweat Rate Fluid Replacement How the Plan is Calculated Drinking Schedule Fluid Balance Context Conditions Matter

Step 1

Start with a measured Sweat Test

The Hydration Planner uses the sweat rate from one of your saved Sweat Tests. Sweat rate represents the estimated amount of fluid lost per hour during that specific test.

The test also preserves useful context such as activity, temperature, humidity, and whether the session was performed indoors or outdoors.

A Sweat Test is a measurement, not automatically a drinking prescription. EnduroPace keeps the measured sweat rate separate from the fluid strategy you choose to build from it.

Learn how to perform the measurement on the Performance Lab Sweat Test guide .

Step 2

Choose Fluid Replacement

Fluid Replacement determines what percentage of the selected measured sweat rate EnduroPace uses to calculate the planned fluid target.

Example:
Measured sweat rate = 1,407 mL/hour
Fluid Replacement = 67%

1,407 × 0.67 ≈ 943 mL/hour

EnduroPace currently uses 67% as an editable starting point. It is not intended to be a universal prescription.

Athletes may need to adjust the target based on experience, thirst, gastrointestinal tolerance, intensity, fluid availability, and expected conditions.

Measured loss does not mean 100% must always be replaced during exercise. The planner allows the athlete to adjust the strategy while preventing a target above 100% of the selected measured sweat rate.

Calculation

How is the Hydration Plan calculated?

Planned Fluid Target

Planned fluid/hour = measured sweat rate × Fluid Replacement

Estimated Sweat Loss

Estimated sweat loss = measured sweat rate × expected duration

Total Planned Fluid

Total planned fluid = planned fluid/hour × expected duration

Modeled Unreplaced Fluid

Modeled unreplaced fluid = estimated sweat loss − total planned fluid

These values are planning estimates. They assume that the measured sweat rate remains reasonably representative of the planned activity.

Execution

Drinking Schedule

The hourly target can be translated into a simple 15-, 20-, or 30-minute drinking interval.

Fluid per interval = planned fluid/hour × interval minutes ÷ 60

Example:
Planned target = 943 mL/hour
Interval = 20 minutes

943 × 20 ÷ 60 ≈ 314 mL every 20 minutes

Context

Fluid Balance and the 2% attention indicator

EnduroPace compares modeled unreplaced fluid with the body mass recorded at the start of the selected Sweat Test.

Modeled fluid deficit % ≈ unreplaced fluid (L) ÷ pre-test body mass (kg) × 100

Because approximately one liter of water has a mass of about one kilogram, this provides useful planning context.

When the modeled value exceeds 2% of the pre-test body mass, EnduroPace displays an ATTENTION message so the athlete can review the expected duration, selected Sweat Test, and Fluid Replacement.

This is not a prediction of exact race-day body-weight change. Actual body mass during prolonged exercise is affected by more than fluid balance alone.

Context

Conditions matter

Sweat rate can change substantially with:

temperature
humidity
sport
exercise intensity
clothing and equipment
heat acclimation
indoor versus outdoor training

For that reason, EnduroPace stores multiple Sweat Tests and allows you to select the test that best represents the planned activity.

EnduroPace does not currently apply an automatic weather multiplier. A measured sweat rate is not silently increased or reduced because a planned event is hotter, cooler, or more humid. Instead, the conditions remain visible so the athlete can choose a more representative Sweat Test.

Units

Metric and imperial display

EnduroPace stores measurements canonically and can display hydration values as milliliters, liters, or fluid ounces.

Changing the display unit does not change the physical Sweat Test or Hydration Plan.

Hydration Planner

Turn a measured Sweat Test into a practical fluid strategy for training and race day.

Measure first. Plan second.

EnduroPace begins with a measured Sweat Test rather than assuming that every athlete loses fluid at the same rate.

The Hydration Planner then combines your measured sweat rate, expected duration, and selected Fluid Replacement percentage to build an hourly target and a simple drinking schedule.

Measured Sweat Rate Fluid Replacement How the Plan is Calculated Drinking Schedule Fluid Balance Context Conditions Matter

Step 1

Start with a measured Sweat Test

The Hydration Planner uses the sweat rate from one of your saved Sweat Tests. Sweat rate represents the estimated amount of fluid lost per hour during that specific test.

The test also preserves useful context such as activity, temperature, humidity, and whether the session was performed indoors or outdoors.

A Sweat Test is a measurement, not automatically a drinking prescription. EnduroPace keeps the measured sweat rate separate from the fluid strategy you choose to build from it.

Learn how to perform the measurement on the Performance Lab Sweat Test guide .

Step 2

Choose Fluid Replacement

Fluid Replacement determines what percentage of the selected measured sweat rate EnduroPace uses to calculate the planned fluid target.

Example:
Measured sweat rate = 1,407 mL/hour
Fluid Replacement = 67%

1,407 × 0.67 ≈ 943 mL/hour

EnduroPace currently uses 67% as an editable starting point. It is not intended to be a universal prescription.

Athletes may need to adjust the target based on experience, thirst, gastrointestinal tolerance, intensity, fluid availability, and expected conditions.

Calculation

How is the Hydration Plan calculated?

Planned Fluid Target

Planned fluid/hour = measured sweat rate × Fluid Replacement

Estimated Sweat Loss

Estimated sweat loss = measured sweat rate × expected duration

Total Planned Fluid

Total planned fluid = planned fluid/hour × expected duration

Modeled Unreplaced Fluid

Modeled unreplaced fluid = estimated sweat loss − total planned fluid

These values are planning estimates. They assume that the measured sweat rate remains reasonably representative of the planned activity.

Execution

Drinking Schedule

The hourly target can be translated into a simple 15-, 20-, or 30-minute drinking interval.

Fluid per interval = planned fluid/hour × interval minutes ÷ 60

Example:
Planned target = 943 mL/hour
Interval = 20 minutes

943 × 20 ÷ 60 ≈ 314 mL every 20 minutes

Context

Fluid Balance and the 2% attention indicator

EnduroPace compares modeled unreplaced fluid with the body mass recorded at the start of the selected Sweat Test.

Modeled fluid deficit % ≈ unreplaced fluid (L) ÷ pre-test body mass (kg) × 100

Because approximately one liter of water has a mass of about one kilogram, this provides useful planning context.

When the modeled value exceeds 2% of the pre-test body mass, EnduroPace displays an ATTENTION message so the athlete can review the expected duration, selected Sweat Test, and Fluid Replacement.

This is not a prediction of exact race-day body-weight change. Actual body mass during prolonged exercise is affected by more than fluid balance alone.

Context

Conditions matter

Sweat rate can change substantially with:

temperature
humidity
sport
exercise intensity
clothing and equipment
heat acclimation
indoor versus outdoor training

For that reason, EnduroPace stores multiple Sweat Tests and allows you to select the test that best represents the planned activity.

Units

Metric and imperial display

EnduroPace stores measurements canonically and can display hydration values as milliliters, liters, or fluid ounces.

Changing the display unit does not change the physical Sweat Test or Hydration Plan.