Water, water everywhere
The more athletic among us already know this, and most dedicated athletes and bodybuilders can be found drinking before, during and after a workout. That’s because we require one milliliter of water for every calorie we burn, according to Nancy Clark, M.S., R.D., author of Nancy Clark’s Sports Nutrition Guidebook and former director of Nutrition Services at Sports Medicine Brookline.
“If your standard workout burns 500 calories,” Clark says, “it should be followed by a minimum of 500 milliliters (about 16 ounces) of water.” Don’t worry, says Clark, that your water intake during exercise will cause cramps. “That’s an old wives’ tale that has no bearing in reality. Drink!”
Clark’s is advice well taken, considering that dehydration brought on by exercise can affect not only an athlete’s performance, but can also cause serious illness besides. For every liter of sweat you lose, your heart rate increases about eight beats per minute (depending on the conditions, you can lose a liter in as little as half an hour). Without adequate fluids, you add stress to your heart, your core body temperature rises and your ability to perform suffers. Your body is unforgiving when its water store dips below normal levels, and even slight dehydration will slow you down.
Dehydration can also affect athletic performance by exacerbating a condition known as cardiovascular drift, a state that occurs during exercise lasting longer than an hour.
Cardiovascular drift is characterized by a progressive increase in heart rate and a corresponding decrease in the amount of blood pumped from the heart with each beat. During prolonged exercise, blood is directed to the surface of the body for cooling to take place. This creates a drop in stroke volume and a reduction in blood returning to the heart. Being adequately hydrated can help prevent cardiovascular drift.
While dodging such medical horrors may be as simple as swallowing sufficient fluids, finding the right water to drink can be downright confounding. While we know that our continued good health is dependent on drinking the stuff, we’re confronted with a great Sargasso Sea of warnings about our nation’s water supply.
Chlorination, the most widely used method of killing bacteria in water, is known to produce potent carcinogenic residues. Batmanghelidj insists that chlorine, an anti-infective agent used to destroy pathogens like bacteria, is a blessing. “We owe chlorine for making our water safe to drink, and for protecting us from cholera and typhoid,” he insists. Others feel differently.
“Chlorine is a killer,” says Boze Berman, a clean-water activist who lives in Glendale. “It breaks down into a variety of carcinogenic chemicals, and not one of them is good for you.”
Indeed, studies have shown that drinking chlorine-treated water doubles the risk of bladder cancer. Chlorination has been linked to clogged arteries and is known to destroy vitamin E in the body, which can lead to heart problems. And published analyses of various municipal water sources have found significant levels of pollutants like lead, mercury, organic solvents and nitrates, which are not removed by our current tap water treatment practices.
Even more shocking is the news that drinking fluoridated water breaks down bone collagen, weakening bones and increasing their susceptibility to fracture. Fluoride – long lauded for its prevention of tooth decay – is the most common toxin used in rat poison. A recent study of more than 150 cancer deaths discovered that fluoride accumulates in the body and may cause cancer and other fatal diseases.
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