Supplement analysis backed by scientific evidence · PT

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Moderate evidencePhysical performance

Electrolyte Powder

Sodium-containing drinks genuinely improve fluid retention and rehydration after heavy sweat losses, and that part is well established. The marketing beyond that (daily hydration, energy, brain fog, cramp prevention) runs far ahead of the evidence for people who are not sweating hard for hours.

What the science says

  • Fluid retention and rehydration after sweat loss Strong evidence

    The ACSM position stand on exercise and fluid replacement concludes that sodium in a rehydration beverage reduces urine output and helps restore plasma volume, and recommends roughly 20-30 mmol/L sodium for exercise exceeding one hour. Beverage hydration index studies confirm sodium-containing drinks are retained better than plain water over 2-4 hours.

  • Preventing exercise-associated hyponatremia Limited evidence

    The 3rd International Exercise-Associated Hyponatremia Consensus Statement identifies excessive fluid intake, not sodium loss, as the primary cause, and states that sodium supplementation does not reliably prevent EAH. Drinking to thirst is the recommended prevention strategy; an electrolyte powder is not insurance against overdrinking.

  • Muscle cramp prevention Limited evidence

    The electrolyte-depletion theory of exercise cramp is poorly supported. Trials of sodium loading show inconsistent effects on cramp susceptibility, and the neuromuscular fatigue model better explains most cramping. Some individuals with very salty sweat and high losses may benefit, but this is not established.

  • Everyday hydration, energy and cognition Limited evidence

    In people eating a normal diet and not exercising heavily, there is no trial evidence that adding an electrolyte powder to water improves energy, focus or wellbeing. Typical Western diets already supply well above the sodium and potassium needed for daily fluid balance.

Dosage & safety

Studied doseFor exercise over one hour or in heat: 460-1150 mg sodium per litre (20-50 mmol/L), 78-195 mg potassium per litre, optionally 6-8% carbohydrate. Ultra-endurance athletes and heavy sweaters often use the higher end (up to about 1500 mg sodium/L). Drink to thirst rather than to a fixed schedule. Oral rehydration solutions for illness follow WHO ratios (about 75 mmol/L sodium with glucose).
SafetyProducts aimed at ultra-endurance can deliver 1000-1500 mg sodium per serving; several servings a day is a substantial sodium load. Avoid or use only under medical guidance with hypertension, heart failure or chronic kidney disease. High-potassium formulas are risky alongside ACE inhibitors, ARBs, or potassium-sparing diuretics such as spironolactone. Electrolyte powder does not protect against hyponatremia caused by drinking too much fluid.

Scientific references

Where to buy

Hydralyte Plus+, Fizzy Electrolyte Powder, Berry Blast, 20 Packets, 0.31 oz (9 g) Each

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