TL;DR Don't choose something with ultra-high amounts of sodium, carbohydrates, or sugar unless you need to based on your exercise levels or a sweat test. Amy Brownstein, a registered dietitian nutritionist at MyNetDiary , says electrolytes are minerals that exist naturally in your body. These include magnesium, calcium, chloride, sodium, potassium, and phosphorous. The role of electrolytes is to help your body rehydrate or stay hydrated by helping your system actually absorb the water you drink. Heather Gosnell, a pediatrician, sodium is the key ingredient for effective rehydration. She also says a little sugar and carbohydrates help your body absorb water but to avoid high-sugar drinks. Electrolyte powders usually contain these, as well as the aforementioned minerals, all of which can help with absorption. But how can you know which powder is best for you?…