But increased activity affects everyone's needs for water. In addition to influencing proper metabolism, water helps keep you cool. Temperature regulation in humans is dependent upon evaporation of perspiration on the skin. Insufficient fluids in the system hamper and slow the body's natural thermostat. Waiting to drink until you're parched is a big mistake.
Weekend warriors face an additional problem.
Artificial cooling acclimatizes the body to performing at those lower temperatures. When those who are unaccustomed to outdoor heat suddenly lace up their Nikes and start running, they may suffer more severe side effects. Give yourself conditioning time, in addition to more frequent sips of water before embarking on outdoor training in summer heat, Weber suggests. That's why the first days of football practice entails a gradual build-up, so that the body can acclimatize. Consume at least 16 ounces of water about two hours before you head outdoors, even if you're planning to merely work in your garden or spend a day on the beach.