Sodium Supplementation and Exercise-Associated Hyponatremia (EAH) during Prolonged Exercise (ultramarathon running)
Weight loss of around 4% body weight (relative to pre race weight) can be anticipated to maintain euhydration in such a prolonged event
Those who become symptomatic with EAH have either gained weight or lost less that 3-4% body weight
Overhydration rather than inadequate supplemental sodium intake is a greater contributor to the development of EAH
There is a suggested link between EAH and rhabdomyolysis. The mechanism remains unknown and it is unclear which condition may augment the other. Further research is needed.
Take home: Avoid overhydration during prolonged exercise to prevent EAH.
References
Sodium Supplementation and Exercise-Associated Hyponatremia (EAH) during Prolonged Exercise (ultramarathon running) Hoffman and Stuempfle 2015.
