Skip to content

Marathon Hydration Plan

Use course access, weather, sweat experience, and thirst to avoid both underdrinking and forced overdrinking.

Plain answerA marathon hydration plan should prevent excessive dehydration without creating weight gain from overdrinking. Needs vary widely with sweat rate, weather, pace, body size, acclimatization, and course access. Practice in comparable conditions; do not force one cup count on every runner.

Map the course first

Find each aid station, the drinks offered, cup or bottle rules, and whether stations can be missed in congestion. Decide where you expect to drink and what you will carry, then rehearse that access.

Source checkACSM Exercise and Fluid Replacement position stand
The guidance recommends individualized fluid-replacement programs because sweat rate and sweat-electrolyte content vary considerably. The aim is to avoid excessive dehydration and disruptive electrolyte changes.

Estimate instead of guessing

Body mass before and after a representative training run, adjusted for fluid consumed and urine, can help estimate sweat loss. Repeat across different conditions. This does not produce a permanent prescription; weather and effort change the result.

Avoid both errors

  • Too little: large fluid deficits can impair performance and increase strain.
  • Too much: drinking beyond losses can create dangerous exercise-associated hyponatremia.

Race the practiced system

Use thirst and the rehearsed plan rather than panic at every station. Electrolyte and carbohydrate drinks can help in some circumstances, but sodium does not make unlimited water safe. Confusion, severe headache, repeated vomiting, collapse, chest symptoms, or other concerning signs require event medical help.

Run More! You can do it!

RunTeaming is a running game for iPhone and Android. Your best qualifying run of the week becomes your score on a five-runner team. The app supplies the team and matches it against another team near its level, so you do not recruit anyone or share a time or location.

Use the button to choose iPhone or Android and see the current installation options.

Try RunTeaming

Run anywhere · No team to recruit · No shared schedule · Choose the installation page for your phone