Sodium Balance & Hyponatremia Risk Checker
Compare what you lose in sweat against your fluid and sodium plan to see whether you're heading toward dehydration, balance, or dangerous over-drinking.
Your sweat & race plan
Get your sweat rate from the Sweat Rate Calculator first.
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How this calculator works
Sodium loss is sweat rate × sweat sodium concentration × duration. We compare it to your planned intake to show a net deficit, and compare planned fluid against sweat rate to flag dehydration or over-drinking. The suggested target replaces about 70% of hourly sodium loss.
Assumptions
- • A representative sweat rate and sweat sodium value
- • Even intake across the race
Limitations
- • Sweat sodium varies widely and is best measured directly
- • Individual hyponatremia risk depends on many factors
Who this is for
- • Triathletes planning hydration for long or hot races
- • Salty sweaters prone to cramping
- • Athletes refining a fluid and sodium strategy
Who this is not for
- • Diagnosing or treating any medical condition
- • Athletes with kidney, heart, or blood-pressure conditions (seek medical advice)
References
Related Articles
Continue exploring our comprehensive triathlon resources
Sodium Balance Calculator FAQ
Scientific References
Consensus guidance on preventing exercise-associated hyponatremia
Reference values for sweat rate and sweat sodium