Water is especially critical for athletes because the body operates optimally only within a narrow range of hydration. Dehydrate a muscle by only 3% and it loses about 10% of its contractile strength and 8% of its reaction speed.
Dehydration disrupts both brain and muscle function. Body fluids thicken to sludge. Without sufficient water, you cannot stimulate liver and kidney function and dispose of toxins through the bile duct into the intestines, and through the urine for elimination. In our highly toxic world, clean water is a must for health.
We see people drinking from public water fountains, or tap water in restaurants, apparently unaware that faucet water in the US and Canada is badly polluted. We have measured it while traveling around lecturing. Usually there are 300 to 500 ppm (parts per million) of dissolved contaminants. We find pesticides, benzene, toluene, lead, mercury, and other industrial chemicals, at levels forbidden in food. Water authorities also add chemicals to enable them to deal with the water. Notable are chlorine used to kill bacteria and aluminum used as a settling agent. You do not want these toxins in your body.
Lets take aluminum as an example. The first solid evidence of brain damage from aluminum in tap water came from the Camelford incident in England in 1988, when excessive aluminum was accidentally added during water treatment and immediately sickened hundreds of people. Ten years later, detailed examination of the brains and the cognition of 55 of them showed massive brain damage.
Despite the evidence, aluminum is still used to treat water supplies. Trace amounts remain in the tap water. You will also find aluminum in some products like deodorants and toothpaste, all of which can be toxic at a cumulative dose received over months of use and ingestion. Aluminum in tap water is now strongly associated with Alzheimer's disease.
There are many other toxins in tap water. Drawing on extensive sources, the New York Times published a series of well-researched articles in December 2009. They found that 20% of the water treatment systems, providing water to 49 million people, had violated key provisions of the Safe Drinking Water Act over the previous five years. Violations included arsenic, uranium, tetrachloroethylene and bacteria. DON'T drink tap water if you value your health.
What about the bottled water alternative. More than 90% of bottled waters are simply tap water put through a casrbon filter to improve the taste. Comprehensive testing of 10 of the largest national brands by the US Environmental Working Group in 2008, found a huge array of toxins in every brand. These bottled waters had an average of eight pollutants per brand, including disinfectants, chloroform, fertilizer, toluene, and man-made carcinogens.
So, what to do? cheap counter-top water filters do not clean tap water. They simply remove obvious bad tastes. The best solution is a home filtration system plumbed into your water line. Options include a steam water distiller that contains a vent to release organic solvents. A cheaper option is a good reverse osmosis system with multiple filters in it, that is plumbed into your water line under your sink. They cost around $300 initially, plus replacement filters at regular intervals. It will produce water at less than 30 ppm pollutants. That's twelve times cleaner than the average tap water.
Over millions of years the human body developed many different defensive mechanisms to detoxify itself. One of the most important of these is water. So make sure you give your body this most important nutrient as clean as you can.
Altman P, et al. Brit Med J, 1999 Sep 25;319(7213):807-11.
Frisardi V, etal. J Alzheimers Dis. 2010;20(1):17-30.
Duhigg C. New York Times, 9 December 2009.
Environmental Working Group. October 2009. http://www.ewg.org/reports.