Health Focus - The Effects of Dehydration Drinking plenty of water each day is a good prescription for staying healthy. The latest research shows that most of you drink less than the optimal amount of water, even though you’ve probably been told since childhood to down eight glasses of aqua a day. If you don’t get enough water, various physical symptoms can result. A rookie in the National Basketball Association, for example, complained of muscle cramps, headaches and fatigue that a dietitian traced to too little water in his diet. Skimpy water intake contributes to constipation and increases the risk of heat exhaustion or heat stroke. Drinking too little water can also be a factor in asthma attacks, dental disease, kidney stones and urinary tract infections and may increase the risk of colds or cancer, according to a report published in Consumer Reports on Health. There’s even a study of 30,000 men in the New England Journal of Medicine showing those who consume the most liquid have roughly half the bladder-cancer risk of those who drink the least amount of fluids. There’s anecdotal evidence that water may decrease the risk of other cancers. If you want to quickly calculate how much water you need on a daily basis, just use this easy formula. Take your weight and multiply by .08. The answer is the number of glasses you should drink. So, if you weigh 150 pounds, you need to drink 12 eight-ounce glasses of water a day. Of course, the amount you need varies depending on your diet, whether you exercise, what the climate is like and other factors. A lot of us suffer mild dehydration, which is when water loss hits about two percent of your body weight. At that point, you should feel thirsty and drink enough to make up for the deficit. Symptoms of mild dehydration include headache, fatigue, lightheadedness, muscle cramps and slightly dulled thinking. Remember, you get about as much water each day from solid foods as you do from beverages. For example, an apple is 84 percent water – about four ounces. Here are some other examples: --Oranges, 87 percent water, or 3.9 ounces --Banana, 74 percent water, or 2.9 ounces --Watermelon (1/2 cup), 74 percent water or 2.5 ounces --Cantaloupe (1/2 cup), 80 percent water, or 2.4 ounces --Grapes (1/2 cup), 81 percent water, or 2.2 ounces In the vegetable category: --Tomatos, 93 percent water, or 3.9 ounces --Cucumber (1/3), 96 percent water, or 3.2 ounces --Potatoes (1/2 cup cooked), 76 percent water, or 2.7 ounces --Broccoli (1/2 cup cooked), 91 percent water, or 2.4 ounces --Iceberg lettuce (1 cup), 96 percent water, or 1.6 ounces Meat also is high in water content, with a sirloin steak being 82 percent water, and hamburger 54 percent water. Shrimp is 77 percent water, flounder is 73 percent and skinless chicken breast is 65 percent. In the grain category, one-half cup of cooked rice is 89 percent water and one-half cup of spaghetti is 66 percent water. A slice of whole wheat bread is 38 percent water. You get the point. There’s plenty of water in food, yet researchers say most people, particularly men, don’t consume enough water. A general rule of thumb is to try to consume from nine to 12 cups of fluid a day in addition to everything else. If you exercise, it’s a hot day or the humidity is high, drink extra. By the way, alcohol and coffee beverages really don’t count since they’re diuretics and tend to cause you to expel as much liquid as you take in. The only time excess water may be harmful is when your body retains water due to congestive heart failure, hypothyroidism, or long-term use of some medications, particularly nonsteroidal anti-inflammatory drugs such as ibuprofen. For most of us, drinking extra water is good preventive medicine for keeping the body healthy. Source: Consumer Reports on Health, November 1999 This article is adapted from Health Central More links: Here's the section in question: "Dehydration in excess of 3-5 percent leads to reduced strength and local muscular endurance, reduced plasma and blodd volume, compromised cardiac output (elevated heart rate, smaller stroke volume), impaired thermoregulation, decreased kidney blood flow and filtration, reduced liver glycogen stored and loss of electrolytes." http://ncaa.org/sports_sciences/sports_med_handbook/2d.pdf Here's a related article that starts about volleyball but goes on to consider the effects of daily low-level dehydration: http://www.usatoday.com/life/health/doctor/lhdoc257.htm Water.com's water intake calculator: http://http://www.water.com/learn_about_water/swg1350_hydcalres.asp Gatorade's "Articles for Athletes" section: http://www.gatorade.com/gssi/articles4athletes.html above links from "William Waggoner" from the newgroup alt.mountain-bike