SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/run-electrolyte-loss-sweat

Why do long sweaty runs increase a runner's need for sodium?

Sweat contains salt, so sodium is lost with it.

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  1. Muscles burn sodium for fuel
  2. Sweat contains salt ✔
  3. Lungs exhale large amounts of sodium

Why: You lose sodium when you sweat. Long or hot runs can drain enough to matter, and heavy sweating is one cause of an electrolyte imbalance.

Huh, didn't know that: Sodium helps control the amount of fluid in your body and helps your nerves and muscles work.

The dad joke
Why did the runner sweat on the saltshaker? They needed a refill.
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References

Answer: Sweat contains salt. You lose sodium when you sweat. Long or hot runs can drain enough to matter, and heavy sweating is one cause of an electrolyte imbalance.

  1. Hyponatremia | Mayo Clinic www.mayoclinic.org/diseases-conditions/hyponatremia/symptoms-causes/syc-20373711
    Because you lose sodium through sweat
    Checked 2026-10-12.
  2. Fluid and Electrolyte Balance | MedlinePlus medlineplus.gov/fluidandelectrolytebalance.html
    Heavy sweating
    Checked 2026-10-12.

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