Mordor Intelligence valued the electrolyte supplement market at $3.4 billion in 2025, propelled by brands like LMNT, Liquid I.V., and Drip Drop. Dr. Stacy Sims (Stanford, exercise physiologist) points out the irony: most adults eating a standard diet and exercising moderately do not need supplemental electrolytes. But specific populations genuinely benefit.
The primary electrolytes are sodium, potassium, magnesium, and calcium. In a standard mixed diet, most people obtain adequate amounts. The exception is potassium and magnesium: NHANES data (2017-2020, n=15,000+) show approximately 48% of Americans consume less than the estimated average requirement for magnesium, and 97% fall below the adequate intake for potassium (4,700 mg/day).
When supplementation does not make sense: sedentary or lightly active individuals eating a normal diet. Dr. Asker Jeukendrup (Loughborough University), who has published over 200 papers on exercise nutrition, notes that a 30-minute gym session typically produces 200-500 mL of sweat containing just 400-800 mg of sodium — easily replenished by a normal meal.
Sodium is the most critical electrolyte during prolonged exercise. The ACSM recommends 300-600 mg of sodium per hour during extended activity in heat. For athletes, sodium replacement prevents exercise-associated hyponatremia, a condition that killed at least 14 marathon runners between 1981 and 2014 (NEJM review by Dr. Tamara Hew-Butler, 2015). For the general population, optimal sodium intake remains debated: a 2022 Lancet study (n=28,880) found the lowest cardiovascular risk at 3-5 g/day, above the AHA's 2,300 mg recommendation.
Magnesium deserves specific attention. Dr. Andrea Rosanoff (CMER, Appalachian State University) has shown that subclinical deficiency is common and underdiagnosed because serum magnesium measures only 0.3% of total body stores. Magnesium glycinate and threonate have the best absorption profiles and least GI side effects. A dose of 200-400 mg elemental magnesium daily is well-supported by a 2017 Scientifica review (k=40, n=3,800+).