While dehydration and electrolyte abnormalities are one hypothesis for the cause of muscle cramps, the overall weight of the evidence suggests otherwise. For example, one trial of Ironman triathletes found no significant differences in post-race body mass losses (i.e., dehydration) and serum electrolytes in those with and without cramps.[1] If cramps were based on system-wide hydration and electrolytes, there is no compelling explanation of how spasms happen in specific muscles. Instead, epidemiologic, animal, and electromyogram data indicate that cramps are more likely due to abnormal muscular control in the spine.[2][3]
If an individual does find that their muscle cramps are improved by hydration and electrolytes, diet is a strong way to apply these therapies. For example, consumption of water-dense fruits for hydration, salt for sodium (caution to those with hypertension), dairy for calcium, and various vegetables, fruits and/or for potassium and magnesium.
Otherwise, focus on rest is important to relieve EAMC.[3] Diet-wise this means focusing on consuming the appropriate daily amounts of meals of carbohydrates, proteins, and fats for a person’s activity level.