Explain electrolyte balance in exercise and the role of sports drinks.

1. 1 · Open in two lines. Sweat removes water and electrolytes, mainly sodium and chloride. Sports drinks replace fluid, sodium and carbohydrate together.
2. 2 · Electrolytes in exercise. Sodium holds water in the blood and drives thirst; potassium works inside cells; heavy salt loss with plain water risks low sodium and cramps.
3. 3 · Draw a table of drink types. [Table: hypotonic, isotonic, hypertonic: concentration, use, examples]
4. 4 · When to use. Over about an hour, in heat and humidity, or for salty sweaters; water for short, cool sessions.
5. 5 · Nutrition link. Homemade drink: 1 L water + 60 g sugar + ¼ tsp salt + lemon ≈ 6% carbohydrate, 26 mmol/L sodium.
6. 6 · Close in one line. The right drink at the right time keeps both fluid and electrolytes in balance.

Scoring tip: Write the ACSM composition (5-10% carbohydrate, 20-30 mmol/L sodium) in one line; it is the fact examiners look for.