Hydration
Potassium
Potassium is an essential electrolyte, but pre-workout potassium has not shown performance or cramp benefits.
How it counts: Not part of the score
We show it on the label and count it as disclosed, but it never affects Dose, any sub-score or the grade. The basis below explains why.
- Clinical dose
- No established clinical dose
- Safety ceiling
- —
- Evidence
- weak
- Category
- Hydration
Evidence summary
Research confidence: low
No reference dose, and not part of the Salty score, which counts sodium only. Potassium is an essential mineral (adult adequate intake 2,600-3,400 mg a day, mostly from food), but no human trial shows potassium taken before exercise improves performance, hydration or cramping at any dose. Sweat carries little potassium, and the one rehydration benefit seen used about 1.4 g after exercise and added nothing to sodium (Maughan 1994). The 440 mg here is 13-17% of a day's adequate intake.
Research sources
- Potassium: Fact Sheet for Health Professionals (NIH Office of Dietary Supplements)(opens in new window)
- Post-exercise rehydration in man: effects of electrolyte addition to ingested fluids (Maughan et al., Eur J Appl Physiol 1994)(opens in new window)
8 men dehydrated ~2%: a 25 mmol/L potassium drink (~1.4 g potassium in the volume drunk) after exercise improved fluid retention vs glucose only, but no better than sodium, and adding it to sodium made no difference
- Physiology of sweat gland function: The roles of sweating and sweat composition in human health (Baker, Temperature 2019)(opens in new window)
Sweat potassium is 2-8 mmol/L, far below sweat sodium. Author is employed by the Gatorade Sports Science Institute (PepsiCo).
- Increased running speed and previous cramps rather than dehydration or serum sodium changes predict exercise-associated muscle cramping (Schwellnus et al., Br J Sports Med 2011)(opens in new window)
209 Ironman triathletes: crampers and non-crampers had no differences in serum electrolytes; electrolyte imbalance is not the cause of exercise cramps