Feeling sluggish? Drink up! Even mild dehydration -- the type brought on by a brisk walk on a warm day -- can cause fatigue, difficulty concentrating, and headaches, according to a new study by researchers at the University of Connecticut. Water is the best calorie-free way to rehydrate, but other drinks, such as iced tea, fruit juice, and coconut water, can contribute to some of your H2O intake, experts say. Thirst is the first indication of mild dehydration, so drink a full glass the moment you feel parched.
Water: the Ultimate Energy Drink
Everyday Food, June 2012