Electrolyte replacement (clinical)

Tier 1 — strong evidence · Hydration · Exercise · Heat illness

Electrolyte-containing oral rehydration solutions are the WHO and ACEP standard of care for dehydration caused by diarrhoea, vomiting, and heat illness. In sports, replacing sodium during prolonged exercise (>60 min) is critical to prevent exercise-associated hyponatraemia — a potentially fatal dilutional condition documented in endurance athletes who over-drink plain water. A 2024 personalised hydration RCT (Li et al., PMID 38732589) confirmed that matching fluid and sodium intake to individual sweat losses significantly prolonged high-intensity exercise time in the heat versus ad libitum…

Dose: Clinical dehydration: WHO reduced-osmolarity ORS formula. Sports use: 300–600 mg sodium per hour during exercise lasting over 60 minutes; individualise to sweat rate and conditions. Potassium 75–200 mg/hour may also be appropriate for prolonged efforts.