Why should a sport person and …

A sport person and athletes drink more water to fluid loss from the body. Fluid loss mainly happens four different ways, of which only some may apply to you and your athletes:

Exercise Intensity: Exercising for hours (like in endurance sports) means a greater need for fluids and an increased need to create a hydration plan to avoid becoming dehydrated.
Sweating: Some athletes sweat more than others, and those that sweat a large amount are at a greater risk of severe dehydration.
Temperature: Exercising in hot weather increases the amount of fluid lost through sweating. Conversely, exercising in the cold can impair the ability to recognize dehydration and also increases the amount of fluid lost through breathing.
Altitude: Exercising at higher altitude has a dehydrating effect on the body and increases the amount of fluid needed to feel sufficiently hydrated.