Jung et al. 2005, hydration, electrolytes and exercise-associated cramps

Journal of Athletic Training study of exercise-associated muscle cramps during calf exercise in the heat. Among those who cramped in both conditions, drinking a carbohydrate-electrolyte beverage more than doubled the exercise time before cramp onset compared with a hypohydration condition. But 69% of participants still cramped even when hydrated and supplemented, showing that dehydration and electrolyte loss are not the sole cause. A lab signal that electrolyte intake can delay experimentally-induced cramp, set against the field evidence that cramps are not caused by electrolyte depletion.