What is the recommended pre-exercise hydration strategy in hot conditions?

What is the recommended pre-exercise hydration strategy in hot conditions?

• A. 5-7 mL/kg 4 hours before
• B. 10-12 mL/kg 2 hours before
• C. 15 mL/kg 1 hour before
• D. No fluids before exercise

Answer: (A)

In hot conditions, start with fluid intake well before you begin exercising. The best approach is to drink about 5–7 mL of fluid per kilogram of body mass roughly four hours before activity. This amount helps ensure you start in a well-hydrated state, supports plasma volume, and gives time for the fluid to be absorbed and for any excess to be cleared if needed, reducing the chance of GI discomfort at the start. For a 70 kg person, that’s about 0.35–0.49 liters. The other options either involve too much fluid too close to start, or no fluids at all, which can leave you dehydrated when heat stress is high.

In hot conditions, start with fluid intake well before you begin exercising. The best approach is to drink about 5–7 mL of fluid per kilogram of body mass roughly four hours before activity. This amount helps ensure you start in a well-hydrated state, supports plasma volume, and gives time for the fluid to be absorbed and for any excess to be cleared if needed, reducing the chance of GI discomfort at the start. For a 70 kg person, that’s about 0.35–0.49 liters. The other options either involve too much fluid too close to start, or no fluids at all, which can leave you dehydrated when heat stress is high.