USATF
Announces Major Change in Running Hydration Guidelines
from Jill Geer -
USA Track
& Field BOSTON – USA Track
& Field (USATF) on Saturday unveiled new fluid-replacement guidelines for
long-distance runners, as well as a major new initiative to educate the
distance-running public about how to properly hydrate.
For athletes in general and
especially for those completing a marathon in more than four hours, USATF
recommends consuming 100 percent of fluids lost due to sweat while racing. This
marks a significant change from the understanding most runners have that they
should be drinking as much as possible and following the guideline to
“stay ahead of your thirst,” which has been held as the standard
recommendation for many years.
Simply put, runners should
be sensitive to the onset of thirst as the signal to drink, rather than staying
ahead of thirst. Being guided by their thirst, runners prevent dehydration
while also lowering the risk of hyponatremia (low sodium), a potentially
dangerous condition increasingly seen as runners have erroneously been
instructed to over-hydrate.
Announced by USATF in
advance of the 2003 Boston Marathon, the new guidelines mark a significant
shift in standard recommendations for fluid replacement. They reflect changes
in scientific thinking as well as changes in the average finishing times of
marathon fields.
“The ‘new running
boom’ has seen more mid-pack and back-of-the-pack runners taking up
marathoning,” USATF CEO Craig Masback said. “The United States now
has 30 million adult runners, a growth that has been tremendous for the sport
and the overall health of Americans. As the national governing body for long
distance running, we consider it vital that we play a key role in educating
athletes of all levels, from the four-hour-plus marathoner to our
Olympians.”
Replacing fluids and
sodium
A potentially fatal
condition, hyponatremia most often occurs in exercise lasting four hours or
longer and results primarily from consuming excessive fluids and is exacerbated
by not replacing sodium losses. Severe cases of may involve grand mal seizures,
increased intracranial pressure, pulmonary edema (fluid in the lungs),
respiratory arrest and even death.
In USATF’s new
hydration guidelines, long-distance runners are instructed to consume 1 liter
of fluid for every liter lost during a race, equaling a 1:1 ratio. Runners can
determine their rate of sweat loss weeks before a race by using the USATF
Self-Testing Program for Optimal Hydration, as described on
www.usatf.org.
Following this
self-determined hydration strategy minimizes risks associated with both
dehydration and over-hydration.
Athletes who have not yet
had the opportunity to perform self-testing should begin their races
well-hydrated – indicated by clear urine – and then drink when
thirsty during their races, rather than drinking constantly as some have
recommended. A sports drink with sodium and other electrolytes is
preferred.
Runners lose not only
water, but significant amounts of sodium and other minerals while sweating
during the course of a marathon. Recommendations of 150 percent fluid
replacement or more could result in runners consuming large quantities of water
during their races, causing a drop in overall sodium levels and, potentially,
hyponatremia.
While proper hydration is
critical for all runners competing in long distance races, those who are on the
course for an extended period of time have a greater risk of dehydration or of
overhydration, which increases the risk of hyponatremia. This risk demands that
runners know how much their bodies need in racing conditions.
Many scientists now view
hyponatremia as just as much of a threat to runners as heat illness and
dehydration, and major papers distributed by the International Association of
Athletics Federations (IAAF) and USATF have described these potential problems
and how to avoid them. (These papers are available on
www.usatf.org.)
Education
USATF this weekend is
issuing a call to action to energize its organizational infrastructure in a
public-education push on the topic of fluid replacement and hyponatremia.
USATF’s 56 Associations and 2,500 local clubs – which serve all 50
states and 80,000 USA Track & Field members will be a starting point for
distributing the recommendations on a grassroots level.
While many runners may
choose to conduct their own self-testing, USATF will work with clubs and
Association to set up clinics at which runners will do the one-hour runs under
supervision to help them best determine their hydration needs.
Other medical
issues
As runners have learned the
importance of hydration during long distance events, dehydration has become a
less prevalent condition. Medical crews at marathon finish lines now are
dealing more with hyperthermia (heat illness), postural hypotension (pooling of
blood in the legs), hyponatremia, and the normal injuries that are common among
marathon runners such as blisters and muscle injuries. Hyperthermia can occur
regardless of hydration levels or the distance of a race. In fact, shorter
races can pose more of a threat due to the faster pace per mile, which causes
greater heat production. An adequately hydrated runner who is running too fast
or pushing herself too hard, especially in hot and humid conditions, can fall
victim to hyperthermia. It is therefore important that athletes adjust their
pace to take into consideration race conditions, slowing their pace as heat and
humidity rises, regardless of how much they may be drinking.
“Postural
hypotension” is experienced when a runner suddenly stops, most commonly at
the finish line. With blood pooling in the legs, there is inadequate blood
supply to the rest of the body and the runner feels faint and can fall down.
This had been thought of as demonstrating dehydration, so the response from
medical teams was to rehydrate these runners. Now, medical personnel can
identify this problem correctly and treat it specifically. Treatment requires
raising the runner’s feet above the head for 3-4 minutes for full
recovery. Runners can avoid postural hypotension by keeping the legs moving,
even with light walking or moderate knee flexing when they otherwise would
stand still at or immediately after the finish or at other locations along the
race course.
For more
information
USATF’s new
guidelines, along with supporting documentation, are explained in two
scientific advisories on the topic.
“Proper Hydration for
Distance Running - Identifying Individual Fluid Needs”, by Douglas Casa,
Ph.D., ATC, FACSM, of the University of Connecticut, is issued by USA Track
& Field.
"IMMDA-AIMS Advisory
statement on guidelines for fluid replacement during marathon running,”
was written by Tim Noakes MBChB, MD, FACSM of the University of Cape Town,
South Africa; and David E. Martin, Ph.D. FACSM, of Georgia State University. It
was published in IAAF New Studies in Athletics, March 2002, pp. 15-24.
These two papers, including
an explanation of the self-test, are now posted on the USATF Web site at
http://www.usatf.org/coaches/library/hydration_casa.pdf
and http://www.usatf.org/coaches/library/hydration_iaaf.pdf
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