We’ve all heard the 8 x 8 prescription: Drink at least eight 8-oz. glasses (64 ounces) of water a day. But where did this rule originate and what is the scientific basis?
Several years ago, a kidney specialist looked into this matter. Turns out, a government report from 1945 stated that the body needs approximately 1 milliliter of water for each calorie consumed (about eight cups for the typical 2,000 calorie diet). The report also included a key bit of information that seems to have been forgotten – that most of this quantity is contained in prepared foods. In other words, much of the body’s water requirement will be obtained from soups, juices, cooked grains, etc.
It’s apparent that one’s diet is a significant factor in determining how much a person needs to drink in order to cleanse and stay hydrated. For example, those consuming high-protein diets need more water to dilute acid byproducts. The body’s requirement will vary widely based on other factors such as climate, condition, and activity level. Summer activities, sports, and hard drumming that induce sweating can increase the risk of dehydration. Dehydration, if not treated, can lead to heat-related illness, such as heat cramps, heat exhaustion, and heatstroke. However, even slight dehydration, as little as 2 percent of body weight, can impair your performance.
Of course, too much of anything, including water, can be bad. I’m reminded of a radio contest several years ago in which a woman died of water toxicity by competing to see who can drink the most water. While some people brag how much water they drink, others are putting their health at risk by not drinking enough. Elderly folks, for example, sometimes forget to drink, which can impair circulation by causing the blood to become too thick.
While quantity will vary among individuals, three important times to drink water are upon awakening (to help elimination), between meals, and during and after physical activity. For events up to one hour, plain water is fine. For longer sets and heavy perspiration, a sports drink containing electrolytes (sodium and potassium) and glucose is best.