There is a powder called “Liquid IV” that my 400M running daughter’s coach swears by, as does my daughter, both sugar-containing and sugar free.
So I’ve bought it.
It works well; I think better than other sports drinks. Not sure why.
https://www.eatthis.com/is-liquid-iv-good-for-you/
Probably because you can add as much electrolyte as you want and not be held to what the mfrs want to put in or not............
Sodium: Essential for fluid balance and helps retain water.
Potassium: Plays a role in maintaining proper water balance and nutrient transport.
Salt: A source of sodium.
Potassium citrate and dipotassium phosphate: Sources of
potassium.
Sodium citrate: Helps balance flavor and is a source of sodium.