Breno's Assistant
Online nowSweat Test Calculator
Determine your individual sweat rate for running and cycling. Create sport-specific hydration strategies based on your unique physiology and the different demands of each discipline.
How to Perform a Sweat Test
Pre-Exercise
Empty bladder, then weigh yourself nude or in minimal dry clothing. Note the exact weight.
During Exercise
Exercise at race intensity for 30-60 minutes. Track all fluids consumed. Avoid urinating if possible.
Post-Exercise
Towel off sweat, remove wet clothes, and weigh yourself again in the same state as pre-exercise.
Calculate
Enter your data below to determine your sweat rate and receive personalized recommendations.
Your Running Results
Sport-Specific Considerations
Personalized Running Recommendations
💧 Fluid Replacement
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🧂 Sodium Strategy
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⏱️ Hydration Timing
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Your Running Hydration Plan
| Time | Fluid Target | Sodium Target | Notes |
|---|
⚠️ Important Considerations
This plan is based on your test conditions. Adjust for race day weather, altitude, and intensity. Remember that sweat rates typically differ between running and cycling - test both sports separately. Practice your hydration strategy during training to ensure tolerance.
The Science Behind Sport-Specific Hydration
- Running: Typically 10-25% higher sweat rates due to less cooling from airflow and more muscle mass activation
- Cycling: Better gut tolerance allows up to 1.5L/hr fluid intake vs 1.0-1.2L/hr when running
- Sodium needs: Often higher in cycling due to longer duration, despite lower sweat rates
- Temperature regulation: Core temp rises faster when running, increasing sweat response
- Practical limits: Running mechanics limit intake to 600-800ml/hr; cycling allows 1000-1500ml/hr
- Gastric emptying: Reduced by 20-50% during running due to mechanical stress and blood flow changes