Electrolytes
Genuinely useful for heavy sweating and endurance work, unnecessary for most everyday workouts.
Not medical advice — anyone with kidney disease, heart conditions, or on blood pressure medication or diuretics should talk to a doctor before regularly supplementing electrolytes.
How It Works
Sodium, potassium, and magnesium are the main electrolytes lost through sweat, and they're what your nerves and muscles use to signal and contract properly. Sweat sodium losses vary enormously between individuals — from roughly 300mg to over 1,800mg per liter of sweat — so "how much you need" is highly individual and depends heavily on how much and how salty you sweat, not just how long you exercise.
The Research: Who Actually Needs This
The strongest, most consistent guidance here comes from sports medicine consensus statements, and it points to a fairly narrow group of people who genuinely benefit from added electrolytes.
Position statement: Casa DJ, et al. "National Athletic Trainers' Association Position Statement: Fluid Replacement for the Physically Active," Journal of Athletic Training, 2017. Provides evidence-based guidance for preventing both dehydration and exercise-associated hyponatremia (overdrinking plain water without replacing sodium) in physically active people.Read the position statement →
Sawka MN, et al. "American College of Sports Medicine Position Stand: Exercise and Fluid Replacement," Medicine & Science in Sports & Exercise. Recommends 0.5–0.7g of sodium per liter of fluid during exercise lasting longer than an hour, primarily to improve fluid retention, palatability, and reduce hyponatremia risk during prolonged effort.
Read the position stand →
Putting the two together, the group that genuinely benefits from deliberate electrolyte supplementation is fairly specific: endurance and ultra-endurance athletes (especially events over 60–90 minutes), people exercising heavily in hot conditions, "salty sweaters" who notice visible salt residue on their skin or clothes, and people with certain medical conditions or on medications that affect electrolyte balance — always worth a doctor's input in that last case.
Who doesn't need it: a normal diet plus plain water comfortably replaces what's lost during typical daily activity or a workout under an hour for most people. A lot of the electrolyte drink mix category is marketed broadly to casual exercisers and even non-exercisers, well beyond the endurance and heat-exposed populations the research above actually supports — worth keeping in mind before treating it as a daily-use product rather than a situational one.
Typical Dosing
For exercise lasting over an hour in the populations above, roughly 0.5–0.7g of sodium per liter of fluid is the range supported by ACSM guidance. Commercial electrolyte mixes vary widely in sodium content (from under 200mg to over 1,000mg per serving) — check the label against how much and how long you're actually sweating rather than assuming more is better.
Who Should Be Cautious
People with high blood pressure, kidney disease, heart failure, or anyone on diuretics or blood pressure medication should talk to a doctor before regularly supplementing sodium or potassium — both can be harmful in excess for these conditions specifically. For most healthy people doing normal daily activity, there's little downside to skipping electrolyte supplements entirely and just eating a normal diet with water.