How To Recognise, Avoid and Treat Hyponatremia

Essentially, hyponatremia is the condition of having a water to sodium imbalance. That is, too much water and too little salt. This occurs in endurance events when athletes overdo fluids that lack sodium or don't have the correct balance of carbohydtrates, proteins and sodium.


For purposes of long distance running, we are concerned primarily with Exercise-Associated Hyponatremia (EAH).

Symptoms may be absent or mild for the early onset of EAH but will inevitably involve impaired exercise performance.

Other symptoms may include nausea, fatigue, vomiting, headache, bloating, muscle weakness, cramping and swelling of hands, legs, and feet. As water retention increases, weight gain may also occur.

This condition tends to affect females much more so than males and smaller athletes rather than larger.

On the Run Cures
  • snack on the salted potato chips which will be available at the main aid station
  • take the Endura sports drink which will be available at the main aid station
  • carry some form of electrolyte replacement, and
  • make sure that you have a supply of salt tabs
If the hyponatremia is not rectified and becomes severe you will almost certainly be unable to finish the 100 mile race. Make sure that you are adequately prepared.
  • Be prepared and have a nutrition plan that you have use in training
  • Be on the lookout for other athletes who may suffer from this condition
  • Do your own research.
  • Enquire of more experienced runners. One such runner is Scott Whimpey of First Aid Accident & Emergency, (our First Aid provider. If in doubt, call Scott on 0427 026 563.