More Information on Hydration
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Bottled Water vs. Tap
BPA-Free Glass Water Bottles
What to Drink, When
Sam Cheuvront should know. He studies hydration for the U.S. Army Research Institute of Environmental Medicine (USARIEM), whose mission is to “protect, sustain and improve the performance of the Warfighter.” Cheuvront spends his days testing soldiers to see how their bodies perform when they’re hot, dehydrated, in humidity, at high altitude and other extreme conditions. At USARIEM in Natick, Massachusetts—where most of Cheuvront’s work is conducted—scientists simulate different environments, putting real soldiers in an assortment of climate chambers, from the Tropics Chamber to the Arctic Chamber. Called the Doriot Climatic Chambers, these are some of the world’s largest and most sophisticated environmental test chambers. Researchers can march five soldiers in full gear on a treadmill built for a horse and pummeled by winds at 100°F while it’s raining, to test exactly how much they’re sweating, their heart rate, how much energy they’re expending and their body temperature. They could even have soldiers simulate living on top of Pike’s Peak in Colorado (atmospheric pressure equal to an altitude of 14,000 feet) for two weeks to see how they fare.
Cheuvront’s studies on hundreds of soldiers have helped create the official military doctrine for how much soldiers need to eat and drink to prevent dehydration and heat stress under a variety of different conditions. To the Army, a hydrated soldier is a tactical weapon.
The intelligence also helps solve other problems. It’s a logistical nightmare to transport water to troops in Iraq and Afghanistan; some soldiers may need more than 3 gallons per day and water transport accounts for one-third of on-the-ground wartime costs. Additionally, water convoys are prime targets for the enemy. Cheuvront recently created formulas for estimating soldier water needs that are 58 to 65 percent more accurate than the old water formula (developed 30 years ago, it overestimated soldiers’ needs). When the new formulas are implemented, the military will no longer ship too much water to troops, saving money and, potentially, lives.Next: How Much Water Do You Need? »