Sodium and chloride (which helps regulate fluids) also can be lost through sweat. So at times, our bodies might need a little more. But while Rosenkranz said most adults don’t need to seek out ways to take in extra electrolytes, she said there’s not a one-size-fits-all answer to the question of who needs extra.
Children who have prolonged periods of vomiting or diarrhea due to illness might be given electrolyte drinks. A child’s body has a greater ratio of body surface to overall weight, Rosenkranz said, so they lose fluids through sweat more easily than adults.
People who work long hours outdoors, particularly in hot, dry climates, or athletes doing “prolonged, vigorous-intensity exercise” might also benefit from an electrolyte drink, she said, as might athletes at higher altitudes, where staying hydrated can be a challenge.
Research on electrolyte supplementation is mostly aimed at athletes, she said. Some sources say that water is fine for anyone in an activity that lasts less than an hour; some say even more activity is needed before anything beyond water is helpful.
Rosenkranz agrees with a general principle that if your exercise lasts less than 75 minutes, and it’s not very high intensity, “then there’s absolutely no need for electrolyte supplementation in those cases. And you can really just hydrate with plain water.”
But, she added, “the reality is that there is a lot of variability in what people need.” It’s not just individual differences in sex, body weight and genetics, she said, but factors such as heat, humidity, how much water someone drank before the activity, the intensity of the activity, and more.
Millard-Stafford, a past president of the American College of Sports Medicine, drew a distinction between sports drinks and electrolyte-infused waters.