It is important to hydrate before and after the race, but it is also important to hydrate while training or during the race.

A proper hydration when running is essential for your wellbeing and performance.  Sport drinks or isotonic drinks such as Gatorade contain electrolytes such as sodium and potassium. When running, the body loses electrolytes through sweat. Given that the electrolytes help the body to retain liquids and to prevent cramps, it is necessary to replace them when running for a period longer than 90 minutes.

The basic rule for hydration during a race is to ingest from 200mL to 300mL of liquid every 20 minutes.