Replace electrolytes when you sweat a lot

In heat or hard exercise, replace sodium and minerals, not just water.

Why it works

Heavy sweating loses both water and electrolytes (especially sodium). Drinking only plain water after big losses can dilute sodium and leave you feeling foggy and fatigued despite "hydrating." Matching fluid with some electrolytes keeps the balance the brain and muscles actually need.

How to do it

1. After heavy sweat from heat or exercise, include some sodium with your fluids.
2. Salt food normally or use an electrolyte drink for prolonged or intense sessions.
3. Don’t overdo plain water after big losses — balance fluid and electrolytes.

Evidence

The role of sodium and electrolyte balance in fluid regulation and in symptoms of over- and under-hydration is well established in exercise and clinical physiology. (mechanistic)

Electrolyte needs vary widely; people with high blood pressure, kidney, or heart conditions should check sodium intake with a clinician.

Common mistake

Drinking large volumes of plain water after heavy sweating, which can dilute sodium and leave you more foggy and fatigued, not less.