What's Up With Water?
by Kim Mueller, MS, RD, Sports Nutritionist
As the most abundant substance in the body, making up 80 percent of our total body weight,
water plays a critical role in optimizing health and enhancing running performance. Helping to
nourish our cells, lubricate our joints, optimize our metabolism and promote peak muscle
function, water is considered an essential nutrient. Unfortunately, water is often the most
neglected nutrient with many runners using thirst or other symptoms like fatigue, itchy skin,
headaches, indigestion and constipation as markers for fluid intake. A recent survey of
approximately 3,000 Americans discovered that 10 percent avoid water altogether, opting for
such dehydrating beverages as caffeinated coffee and tea, soda or alcohol instead. The average
American consumes only six eight-ounce servings of water a day, which, for many, falls short of
the goal fluid intake-about 50 percent of your total body weight (in pounds) in fluid
Runners and walkers, who lose additional amounts via sweat as exercise, require additional
amounts of water as compared to more sedentary people. In addition to drinking half their body
weight in fluid ounces at rest, runners should consume 5-12 ounces of water every 15-20 minutes
of a run lasting less than an hour (sports drinks should be consumed rather than plain water
during runs lasting more than an hour).
However, runners do not often replace an adequate amount of fluid to avoid performance declines
from dehydration. A recent study conducted on runners completing a 10-mile race found that they
tended to underestimate their sweat losses by an average of 46 percent and their fluid intake
by an average of 15 percent, resulting in the runners replacing only 30 percent of fluids lost
through sweat. And a lack of fluid definitely adds up on the course. In fact, a mere two
percent dehydration (equal to a loss of three pounds in a 150-pound runner) during a 10-mile
race can cause a runner to slow down by as much as three-and-a-half minutes. Furthermore,
dehydration inhibits recovery. Runners need to consume 16-24 ounces of fluid for every pound
lost during a run. Dehydration becomes life-threatening when 10-20 percent of body weight is
Fortunately, there is a multitude of types of water available on the market today to suit any
palate and help you stay on top of your fluid game.
Plain Ol' Water in a Bottle
Plain ol' water comprises a third of the total fluid consumed by Americans today, with some 40
percent opting to drink bottled water over tap water. Why the preference? Some bottled water
users claim that bottled water is "safer" than tap water, though stricter safety
standards actually exist for tap water. Others believe that bottled water is "better for
you." However, there is little scientific evidence indicating any nutritional benefit over
your local water supply, which may also include small amounts of such beneficial minerals as
calcium and magnesium. The majority of bottled-water drinkers actually choose to drink bottled
water for its mere convenience. There are actually several different varieties of bottled water
from which to choose.
Distinguished from other types of bottled water by its constant level and relative proportions
of mineral and trace elements at the point of emergence from the source. No minerals can be
added to this product. Manufacturers claim that mineral water is very beneficial for the
Examples: Fiji, Sephora and King Milos.
Oxygenated water uses a process that dramatically elevates the level of dissolved oxygen in the
water. There's been a recent influx of oxygenated waters with the claim, "the body absorbs
the extra oxygen, resulting in improved stamina and athletic performance, reduced recovery time
and better mental clarity." While intriguing, a recent study coordinated by the American
Council on Exercise found that drinking super oxygenated water had NO measurable effect on the
subjects' resting heart rate, blood pressures or blood lactate values, indicating there was no
performance benefits from the enhanced water as compared to tap water.
Examples: Aqua Rush, AquOForce and Athletic Super Water.
Purified water is produced by distillation, deionization, reverse osmosis or other suitable
processes and meets the definition of purified water in the United States. It may contain added
minerals such as calcium, magnesium and potassium. Penta-Hydrate is unique compared to some of
the other purified waters on the market in that it is created through a seven-step process that
removes impurities and chemicals as well as creating a smaller cluster of water molecules for
enhanced water absorption. One study conducted at University of California San Diego
demonstrated a 14 percent faster absorption rate with the Penta as compared to tap water.
Other examples: Aquafina, Dasani and Smartwater.
Water that, after treatment and possible replacement with carbon dioxide, contains the same
amount of carbon dioxide that it had at emergence from the source. Sparkling water has a
refreshing, crisp, clean taste.
Water derived from an underground formation from which water flows naturally to the surface of
the earth. Spring water is a safe water, with a clear, clean taste no other drinking water can
Examples: Arrowhead, Deer Park, Evian, Ozarka and Poland.
Flavored and Enhanced Waters
A common excuse for not drinking enough water, whether it is tap or bottled water, is a dislike
for the taste. These days, however, there is a multitude of flavored beverages designed to
provide a tasty alternative to plain water while avoiding the calorie punch of such other
flavored beverages as fruit juice and sodas. Also packed with vitamins, minerals and possibly
some herbal supplements, flavored waters tend to make a wide variety of claims, including
"rejuvenate, replenish and restore the body," "boost metabolism,"
"neutralize free radicals" and "enhance stamina and brain power." While
these claims are intriguing, they are not necessarily backed by scientific research, which
means drinking the beverage probably won't fulfill the claims made by the company. However, if
you find it hard to palate plain water, flavored waters will offer some benefit to your
Most flavored waters do not contain a significant amount of carbohydrate and electrolytes and
therefore should not be used as your sole hydrating beverages during runs lasting greater than
Examples: Gatorade's Propel Fitness Water, Glaceau Vitamin Water, Reebok Fitness Water and
Whether you choose to drink bottled water or tap water, both are guaranteed to provide you with
the fluid you need for proper hydration both during the day as well as during runs lasting less
than an hour. Aim at drinking half your body weight (in pounds) in fluid ounces on a daily
basis plus an additional five to 12 ounces every 15 minutes during runs lasting less than an
hour. For those who are bored with drinking plain water, use flavored waters to help promote
proper hydration. Remember, though, that the vitamins and minerals in flavored waters most
likely won't enhance your performance and health and should not replace the vitamins and
minerals received from whole foods.
Whatever the water you choose, it is the quantity rather than type of beverage you consume that
will dictate your running performance. And remember that although water is appropriate for runs
lasting less than an hour, sports drinks are more desirable during longer runs due to the
presence of carbohydrate for glycogen repletion and electrolytes for fluid absorption and
optimal muscle function. Cheers!
About the Author: Kimberly J. Mueller, MS, RD is a Registered Sports Dietitian and
competitive endurance athlete who provides nutritional counseling and meal planning to athletes
all around the world. She can be reached at firstname.lastname@example.org.