Athletes, people trying to lose weight, and even the general public are instructed to ensure high levels of hydration through out the day. Ingesting non-diuretic and non-damaging (ie alcohol) fluids help the body to maintain normal function of the organs, encourages homeostasis within all systems of the body, and keep the physiological stress of the tissues at a lower level. Fluids provide a sensation of fullness (one of the reasons they benefit weight loss), and also encourage mental alertness. People who struggle to get through the day (headaches, hunger pangs, fatigue) are often alleviated by increasing the intake of fluids. Thirst has been said to be a poor indicator of hydration because by the time the thirst mechanism is activated, it is too late. Urine color has shown to be a better indicator where lighter urine color (lemonade-like) is ideal versus a darker color (apple juice color). Note that some vitamins and foods will have an effect on color regardless of exertion and fluid intake.