Do I need electrolytes when running?
For runs under 60 minutes in moderate temperatures, water is enough. For runs over 60-90 minutes or in heat, add electrolytes — especially sodium (300-500 mg per hour). Electrolyte loss causes cramping, fatigue, and in extreme cases hyponatremia. Use salt tablets, electrolyte drinks, or salty snacks during long efforts.
Electrolytes — mainly sodium, potassium, magnesium, and calcium — regulate muscle contraction, nerve signaling, and fluid balance. Running depletes them through sweat, and sodium is by far the most important to replace. Typical sweat sodium loss: 300-800 mg per liter of sweat, so a runner losing 1 liter per hour needs to replace at least 300-500 mg of sodium per hour on long efforts. For runs under 60 minutes at moderate temperatures (15-22°C), water alone is sufficient. Your body has enough reserves, and overloading electrolytes isn't helpful. For runs of 60-90 minutes, electrolytes are optional but helpful, especially in warm weather. For runs over 90 minutes or races of any length, electrolytes become important — either through sports drinks, electrolyte tablets (Nuun, SaltStick, LMNT), or salted foods (pretzels, boiled potatoes with salt). Signs of electrolyte imbalance: muscle cramps late in long runs, excessive fatigue, headaches, salt crystals on your skin after running. Signs of hyponatremia (dangerous low sodium): nausea, confusion, swelling, especially after long hot races where you drank lots of water without salt. This is a medical emergency. Heavy sweaters and runners in hot climates like India need more — often 500-700 mg of sodium per hour during long efforts. Experiment during training to find your tolerance and what works.