Electrolytes

Electrolytes are ionized minerals essential for maintaining water balance, muscle and nerve function and blood pH. The main ones are sodium, potassium, magnesium, calcium and chloride. They are lost through sweat during exercise — human sweat contains mainly sodium (20–80 mmol/L) and potassium (4–8 mmol/L). Electrolyte replenishment is especially important in exercise lasting more than 60–90 minutes, in hot environments or for people who sweat a lot (heavy sweaters). Simple hydration with pure water can dilute plasma electrolytes — a situation called dilutional hyponatremia.

• Maintenance of water balance during exercise
• Prevention of muscle cramps from electrolyte imbalance
• Improved performance in prolonged exercise or heat
• Prevention of hyponatremia in long exercise with high water intake
• Maintenance of neuromuscular function
• Faster recovery after intense exercise
• Support for cellular hydration

• •Endurance athletes with training sessions over 60–90 minutes
• •Practitioners of sports in hot and humid environments
• •People who sweat a lot (heavy sweaters)
• •Athletes with history of muscle cramps
• •People who train fasted or with low sodium intake
• •Ketogenic diet practitioners (greater electrolyte loss)

Varies according to the product and exercise intensity. General reference for long exercise: 500–700mg of sodium per hour of intense exercise, with potassium, magnesium and calcium in smaller proportions. Conventional sports drinks: 300–500ml every 15–20 minutes during exercise.

For most people who train for less than 60 minutes in an air-conditioned environment, electrolyte replenishment is not necessary — water is sufficient. For longer training, heat or heavy sweaters, replenishment is important. When choosing: (1) Prioritize products with sodium as the main electrolyte — it is the most lost in sweat. (2) Check if it contains potassium, magnesium and calcium. (3) Prefer versions without added sugar if the goal is fat loss. (4) Effervescent tablets and powders are more convenient than ready-to-drink beverages. (5) Ketogenic diet significantly increases electrolyte needs — especially sodium and magnesium.

Evidence for electrolyte replenishment in prolonged exercise is solid. Studies show that loss of 2% of body weight in sweat reduces performance by 10–20%. Adequate sodium replenishment prevents hyponatremia — a potentially fatal condition in ultramarathon runners who drink excessive water. Sodium is the most important electrolyte for water retention and should be the main component of sports drinks. Magnesium and potassium have a secondary but important role in muscle function and cramp prevention.

Excess sodium may cause hypertension in sensitive people. Excess potassium (hyperkalemia) may cause heart problems — real risk only at very high doses or in people with kidney failure. Sports drinks with sugar contribute unnecessary calories for people seeking fat loss.