You can always make your own sports drink, starting with the recipe from the World Health Organization:

https://www.who.int/publications/i/item/WHO-FCH-CAH-06.1

Just 4 ingredients:

Glucose, anhydrous (dextrose)

Sodium chloride (salt)

Potassium chloride

Trisodium citrate, dihydrate

Of course, the batch size of 75 kg may not be the most convenient for home use, but it's easy to scale down.