Your Health
Athletes Run Risk of Over-Hydrating

Listen to this story... by Allison Aubrey

A runner pours a bottle of water over his head.

There is such a thing as too much water; excessive intake can dilute
levels of sodium in the blood. IStockPhoto



Hydration Tips

University of Connecticut researcher Douglas Casa says people get into
trouble when they try to follow set requirements for hydration.

Scroll below for more tips on how to figure out what's the right
amount to drink for your body.



Morning Edition, August 10, 2006 · If you're training for a marathon
or an Ironman, a hydration plan is important. Of course, there's the
risk of dehydration. But athletes now know they can also get into
trouble by drinking too much. Excessive water intake can dilute levels
of sodium in the blood. The death of a 28-year-old woman following the
Boston Marathon caught the attention of many runners and led to new
research.

Experts advise long distance runners to replace the liquids they sweat
out.

"Our goal is to try to keep someone from not getting dehyrdated by
more than 2 percent of their body weight," says Douglas Casa, a
researcher at the University of Connecticut's Human Performance
Laboratory.

One technique for calculating how much fluid you need is to get an
accurate scale. Runners can weigh themselves before and after a run to
determine how much water weight they've lost. If they're weight drops
by more than 2 percent, they have not consumed enough fluid.

Hyponatremia occurs when runners drink so much liquid that
concentrations of sodium in the blood drop off. A study published in
the New England Journal of Medicine last year tracked 488 runners who
completed the Boston Marathon and found 13 percent of them had
dangerously low blood salt levels.

The first symptoms that runners may notice is minor swelling in the
hands. "They can't get their rings off, then they might get nausea and
dizziness. They may not remember where they are" says Dr. Lewis
Maharam, who directs the International Marathon Medical Directors
Association.

Most runners get enough salt to restore normal levels by eating just
one meal after a run, and most never need medical attention. But with
a spate of reported cases of hyponatremia, Maharam's group has a new
guideline for hydrating.

The recommendation is contrary to the old advice that runners should
drink as much as they can stomach to prevent dehydration.

"The new research has shown that the body is a remarkable machine that
actually tells you via thirst when you need fluid," says Maharam.

Performance-oriented runners may prefer the more exacting
scale-weighing technique. Douglas Casa recommends that runners use
that method until they start to get a good estimate of how much water
they sweat out during a typical training run.
Everyday Hydration Tips

Dr. Douglas Casa, Director of Athletic Training Education in the
University of Connecticut's Neag School of Education says people get
into trouble when they try to follow set requirements for hydration. A
magazine article that endorses eight glasses of water a day may not be
right for you. Quench your thirst for information with Dr. Casa's tips
on how to regulate your daily drinking.

Peek at Your Pee: Monitor its color. If it's light, like lemonade,
you're doing pretty good. If it's darker, like apple juice, start
gulping down liquids.

Step on the Scale: And do it both before and after exercising, to get
a better sense of your individualized hydration needs. If you weigh
more after a workout, chances are you drank too much while exercising.
If you weigh much less, you may need to drink more. Experts recommend
losing no more than 2 percent of your body weight during activity.
Weighing the same before and after exercise, or slightly less,
suggests you are an efficient hydrator.

Consider Sports Drinks: Because they replace some of the salts you
lose when sweating, they're ideal for activities that last longer than
an hour (for instance, hiking or biking treks) or even during very
intense activities. Or if you're the kind of fanatic who's jogging in
110-degree heat.

Remember Chug Capacity: Recent studies show that coffee doesn't
dehydrate, but Casa still doesn't recommend it for a workout; it's not
the kind of fluid you can chug when you need to replace a lot of fluid
in a short period of time.

(But Not for Beer!:) Alcohol does not leave you in the best possible
state to recognize your fluid needs, prepare for the next bout of
activity, or maximize fluid retention. Only use if stranded on an
island with a case of beer, not for the purpose of fluid replacement.

Shun Sugar: Sodas, fruit juices and even beer have a higher level of
sugar (which means more calories per serving) than most sports drinks
or water. These drinks can rehydrate your body because they contain
water, but their sugars give the stomach and intestines more to deal
with; as a result, the fluids aren't absorbed into the body as
quickly. It's fine to drink these beverages with meals and during
leisure activities, but they won't keep you optimally hydrated during
exercise.