Beat the Heat: Hydration 101
As summer temperatures soar, the need for adequate hydration becomes increasingly important, especially for active individuals. Consuming water and electrolytes in sufficient amounts is crucial for normal cellular function and thermal regulation.
As ambient air temperature rises, the body's ability to thermoregulate becomes increasingly difficult. Other factors such as humidity, air velocity and thermal radiation also impact the body's ability to thermoregulate. During physical activity, or any time external heat becomes a factor, inadequate fluid intake can have detrimental effects such as heat cramps, heat exhaustion and even heat stroke.
To avoid this, it is imperative to maintain adequate fluid balance. Two hours before activity, consuming at least 16 fluid ounces has been found to provide adequate hydration if the individual is already well hydrated. During activity, 6 to 8 fluid ounces of water or electrolyte beverage should be consumed every 15 minutes. It's important to note that usually water consumption is sufficient unless the activity lasts longer than 90 minutes, at which point electrolyte beverages are also recommended.
After any activity, individuals should replenish fluids at a rate of 16 ounces per pound of body weight lost during the exercise. Many athletes may need to consume an extra 3-4 gallons of fluid to replace fluid lost during events or lengthy workouts. Ideal fluid replacement depends on the duration and intensity of the activity, ambient air temperature and individual variation.
August 10, 2006
Writer: Tiffany Reiss, PhD, chair of Exercise Science and Wellness, Bastyr University
Republished with permission from Seattle Post-Intelligencer