Final answer:
Thirst is a valid indicator of hydration, but relying solely on it may not be sufficient. Overhydration can be dangerous. Sports drinks are recommended for long exercise sessions or in hot conditions. Most sports drinks have a lower sodium concentration than in the body.
Step-by-step explanation:
Thirst is indeed a valid indicator of hydration status. When the body is dehydrated, it sends signals of thirst to prompt the individual to drink water and rehydrate. However, relying solely on thirst may not be sufficient as thirst can sometimes be delayed or not accurately reflect the actual level of dehydration.
Overhydration, known as water intoxication, can indeed be dangerous and potentially lead to death. When someone drinks excessive amounts of water, it can disrupt the balance of electrolytes in the body, particularly sodium, which is necessary for proper nerve and muscle function.
Sports drinks are recommended for exercise sessions lasting more than an hour or in hot and humid conditions. These drinks contain carbohydrates and electrolytes to help replenish energy stores and replace lost fluids and electrolytes through sweat.
Most sports drinks actually have a lower sodium concentration than that found in the body. The concentration of sodium in most sports drinks is around 20-30 millimoles per liter, whereas the concentration in the body is typically around 135-145 millimoles per liter.
Learn more about hydration of exercise