04HYDRATION · FIELD TEST
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Measure sweat rate from a real session.

Use before-and-after body mass, fluid consumed, urine loss and session time to calculate an observed sweat rate for those conditions.

Works offline after your first visit · installs as its own app · saves on this device
FIELD-TEST INPUTS

Record what actually happened.

Repeat the test across different temperatures, intensities and sports. One result is a measurement of one session—not a permanent personal constant.

MEASURED RESULT

0.88 L/hour

Estimated sweat loss1.10 L
Body-mass change0.8%0.60 kg
Observed fluid replacement45%of estimated sweat loss
CALCULATION

(72.4 kg − 71.8 kg + 0.50 L − 0.00 L) ÷ 1.25 h

Warm, steady run · 26°C
THE NUMBER IS THE START

Put the result in the context of your training.

Form connects sessions, goals, recovery and constraints so the next decision is about more than one calculator.

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