Post by sabretooth on May 12, 2005 16:21:00 GMT 8
found this in PCN.
For those who adhere to to the old adage of "drinking before your thirst".
Those addicted in badminton / endurance sports, hiking, or other strenous
exercises. Read this otherwise unthinkable fatal occurrence.
(a.) "Danger in too much fluid intake in Sports" (May 8, 2005)
by Arturo C. Ludan, MD, Health Notes section
The Philippine Star (http://www.philstar.com)
(an excerpt of the Sunday column)
. . . . Yet hyponatremia is entirely preventable. As The New York Times articles
written by Gina Kolata explains. "during intense exercise the kidneys cannot
excrete excess water as the body secretes a hormone that stops the excretion of
the excess water via urine. As people keep drinking, the extra water moves into
their cells, with no room to expand, press against the skull and compress the
brain stem, which controls vital functions like breathing. The result can be
fatal." . . . .
. . . . The intake of excessive amounts of these low-sodium fluids causes acute
dilutional hyponatremia and reduced plasma volume. The body reacts to the
reduced plasma by secreting the antidiuretic hormone (ADH). The ADH shuts off
the excretion of free water in the urine resulting in the retention of these
fluids and, hence, the weight gain instead of weight loss. Physical exercise and
stress also stimulate ADH secretion. . . . .
. . . . That year, a 28-year old woman reached Heartbreak Hill, at mile 20,
after five hours of running and drinking sports drinks. She struggled to the
top. Feeling terrible and assuming she was dehydrated, she chugged 16 ounces of
the liquid. She collapsed within minutes. She was later declared brain dead. Her
blood sodium level was dangerously low, at 113 micromoles per liter of blood,
(Hyponatremia starts at sodium levels below 135 micromoles, when brain swelling
can cause confusion and grogginess. Levels below 120 can be fatal)". . . . .
. . . . Need for improved Sports drinks . . . a need to reformulate currently
available low-sodium sports drinks. These sports drinks also have high sugar
content which can cause osmotic diarrhea. It is unphysiologic for oral fluid
rehydration due to its high osmolarity of 330 mosm/L which impairs sodium
absorption . . . .
(b.) Hydration: How Much Should We Drink? (Hyponatremia vs Dehydration)
www.webeuler.com/runners/hydration-new-final.htm
(c.) "How Much Water Do You Need When You Run? " (Friday, April 15) Parallel
Universes (http://emeritus.blogspot.com/)
Just enough. And never too much.
A new study debunks the usual adage of marathon runners of the
"drink-ahead-of-your-thirst" mindset to prevent dehydration. The study
emphasizes its point by saying that drinking too much fluids might endanger the
lives of runners.
~ ~ ~ ~ ~ ~ ~ ~ ~
Study Cautions Runners to Limit Their Water Intake
By Gina Kolata, NYTimes
After years of telling athletes to drink as much liquid as possible to avoid
dehydration, some doctors are now saying that drinking too much during intense
exercise poses a far greater health risk.
An increasing number of athletes --- marathon runners, triathletes and even
hikers in the Grand Canyon --- are severely diluting their blood by drinking too
much water or too many sports drinks, with some falling gravely ill and even
dying, the doctors say.
New research on runners in the Boston Marathon, published today in The New
England Journal of Medicine, confirms the problem and shows how serious it is.
The research involved 488 runners in the 2002 marathon. The runners gave blood
samples before and after the race. While most were fine, 13 percent of them ---
or 62 --- drank so much that they had hyponatremia, or abnormally low blood
sodium levels. Three had levels so low that they were in danger of dying.
The runners who developed the problem tended to be slower, taking more than four
hours to finish the course. That gave them plenty of time to drink copious
amounts of liquid. And drink they did, an average of three liters, or about 13
cups of water or of a sports drink, so much that they actually gained weight
during the race.
The risks to athletes from drinking too much liquid have worried doctors and
race directors for several years. As more slow runners entered long races,
doctors began seeing athletes stumbling into medical tents, nauseated, groggy,
barely coherent and with their blood severely diluted. Some died on the spot.
[NYtimes Health, 14 April 2005]
Read the full text of the study
content.nejm.org/cgi/content/full/352/15/1550.
~ ~ ~ ~ ~ ~ ~ ~ ~
Putting it simply, the authors of the study say that if you plan to run and
drink too much, you are in effect diluting your body's electrolyte supply ---
notably sodium --- and exposing yourself to a condition known as hyponatremia or
low concentrations of sodium in your blood, which is harmful and can kill you.
How much should you drink then, if you plan to run?
Take this sound advice from expert doctors:
* Dr. Tim Noakes, a hyponatremia expert at the University of Cape Town -
"For their part, runners can estimate how much they should drink by weighing
themselves before and after long training runs to see how much they lose - and
thus how much water they should replace."
* Dr. Marvin Adner, the medical director of the Boston Marathon - "Don't start
chugging down water. Wait until (you) begin to urinate, (which is) a sign the
body is no longer retaining water."
* Dr. Paul D. Thompson, a cardiologist at Hartford Hospital in Connecticut and a
marathon runner - "Drink while you are moving. If you stop and drink a couple of
cups, you are overdoing it."
Next time you run, remember that the real danger might not really be
dehydration, but drinking too much water. Be careful, okay?
(d.) Hyponatremia (Health & Disease Information)
www.hmc.psu.edu/healthinfo/h/hyponatremia.htm
(e.) What is Hyponatremia? www.geo-outdoors.info/hyponatremia.htm
(f.) Hyponatremia - Wikipedia, the free encyclopedia
en.wikipedia.org/wiki/Hyponatremia
(g.) Facts on Hyponatremia www.honoluluclub.com/pulse.php?ID=31
(h.) Drink Water!
www.MensHealth.com/cda/article/0,2823,s1-1-0-0-1558,00.html
Let water work for you
It's warm now, so remember: Your muscles need H2O to work at peak efficiency.
Plan ahead-- by the time your brain tells you you're thirsty, your body's fluids
are depleted, says Larry Kenney, Ph.D., president of the American College of
Sports Medicine. Everyone sweats at a different rate, based on heredity, fitness
level, and degree of acclimatization to surroundings.
Drinking
Start drinking water at least 15 minutes before beginning your activity. The
rule of thumb is to drink 8 ounces of water for every 20 minutes of exercise.
Where it Goes (in descending amounts)
1. Urine
2. Sweat
3. Evaporation (other than sweat)
4. Metabolic processes (water used inside the body) and respiration (water lost
while exhaling). Both are negligible amounts compared with the first three
Your Sweat rate
Weigh yourself before and after a workout, and subtract the weight of any water
you drank while exercising. If the before-and-after difference is . . .
* 2 percent of your body weight, your athletic performance suffered.
* 3 to 4 percent of your body weight, there are potential health risks,
including elevated heart rate and body temperature.
Refueling Rule
For every pound of body weight you've lost during the workout, drink 16 ounces
of water. Then remember that guideline for your next workout. So if you're 2
pounds lighter after an hour-long run, drink 32 ounces more before or during
your next run. Sound like more than you can swallow? Kenney says some people
find that they can drink more of a sports drink than of water.
The Urine Test
If your urine looks more like iced tea than lemonade, you're dehydrated. The
closer to clear, the better.
Related Articles:
* 5 Ways to Add More Fiber
* 5 Abs Building Tricks
* Get Milk (and lose body fat)
For those who adhere to to the old adage of "drinking before your thirst".
Those addicted in badminton / endurance sports, hiking, or other strenous
exercises. Read this otherwise unthinkable fatal occurrence.
(a.) "Danger in too much fluid intake in Sports" (May 8, 2005)
by Arturo C. Ludan, MD, Health Notes section
The Philippine Star (http://www.philstar.com)
(an excerpt of the Sunday column)
. . . . Yet hyponatremia is entirely preventable. As The New York Times articles
written by Gina Kolata explains. "during intense exercise the kidneys cannot
excrete excess water as the body secretes a hormone that stops the excretion of
the excess water via urine. As people keep drinking, the extra water moves into
their cells, with no room to expand, press against the skull and compress the
brain stem, which controls vital functions like breathing. The result can be
fatal." . . . .
. . . . The intake of excessive amounts of these low-sodium fluids causes acute
dilutional hyponatremia and reduced plasma volume. The body reacts to the
reduced plasma by secreting the antidiuretic hormone (ADH). The ADH shuts off
the excretion of free water in the urine resulting in the retention of these
fluids and, hence, the weight gain instead of weight loss. Physical exercise and
stress also stimulate ADH secretion. . . . .
. . . . That year, a 28-year old woman reached Heartbreak Hill, at mile 20,
after five hours of running and drinking sports drinks. She struggled to the
top. Feeling terrible and assuming she was dehydrated, she chugged 16 ounces of
the liquid. She collapsed within minutes. She was later declared brain dead. Her
blood sodium level was dangerously low, at 113 micromoles per liter of blood,
(Hyponatremia starts at sodium levels below 135 micromoles, when brain swelling
can cause confusion and grogginess. Levels below 120 can be fatal)". . . . .
. . . . Need for improved Sports drinks . . . a need to reformulate currently
available low-sodium sports drinks. These sports drinks also have high sugar
content which can cause osmotic diarrhea. It is unphysiologic for oral fluid
rehydration due to its high osmolarity of 330 mosm/L which impairs sodium
absorption . . . .
(b.) Hydration: How Much Should We Drink? (Hyponatremia vs Dehydration)
www.webeuler.com/runners/hydration-new-final.htm
(c.) "How Much Water Do You Need When You Run? " (Friday, April 15) Parallel
Universes (http://emeritus.blogspot.com/)
Just enough. And never too much.
A new study debunks the usual adage of marathon runners of the
"drink-ahead-of-your-thirst" mindset to prevent dehydration. The study
emphasizes its point by saying that drinking too much fluids might endanger the
lives of runners.
~ ~ ~ ~ ~ ~ ~ ~ ~
Study Cautions Runners to Limit Their Water Intake
By Gina Kolata, NYTimes
After years of telling athletes to drink as much liquid as possible to avoid
dehydration, some doctors are now saying that drinking too much during intense
exercise poses a far greater health risk.
An increasing number of athletes --- marathon runners, triathletes and even
hikers in the Grand Canyon --- are severely diluting their blood by drinking too
much water or too many sports drinks, with some falling gravely ill and even
dying, the doctors say.
New research on runners in the Boston Marathon, published today in The New
England Journal of Medicine, confirms the problem and shows how serious it is.
The research involved 488 runners in the 2002 marathon. The runners gave blood
samples before and after the race. While most were fine, 13 percent of them ---
or 62 --- drank so much that they had hyponatremia, or abnormally low blood
sodium levels. Three had levels so low that they were in danger of dying.
The runners who developed the problem tended to be slower, taking more than four
hours to finish the course. That gave them plenty of time to drink copious
amounts of liquid. And drink they did, an average of three liters, or about 13
cups of water or of a sports drink, so much that they actually gained weight
during the race.
The risks to athletes from drinking too much liquid have worried doctors and
race directors for several years. As more slow runners entered long races,
doctors began seeing athletes stumbling into medical tents, nauseated, groggy,
barely coherent and with their blood severely diluted. Some died on the spot.
[NYtimes Health, 14 April 2005]
Read the full text of the study
content.nejm.org/cgi/content/full/352/15/1550.
~ ~ ~ ~ ~ ~ ~ ~ ~
Putting it simply, the authors of the study say that if you plan to run and
drink too much, you are in effect diluting your body's electrolyte supply ---
notably sodium --- and exposing yourself to a condition known as hyponatremia or
low concentrations of sodium in your blood, which is harmful and can kill you.
How much should you drink then, if you plan to run?
Take this sound advice from expert doctors:
* Dr. Tim Noakes, a hyponatremia expert at the University of Cape Town -
"For their part, runners can estimate how much they should drink by weighing
themselves before and after long training runs to see how much they lose - and
thus how much water they should replace."
* Dr. Marvin Adner, the medical director of the Boston Marathon - "Don't start
chugging down water. Wait until (you) begin to urinate, (which is) a sign the
body is no longer retaining water."
* Dr. Paul D. Thompson, a cardiologist at Hartford Hospital in Connecticut and a
marathon runner - "Drink while you are moving. If you stop and drink a couple of
cups, you are overdoing it."
Next time you run, remember that the real danger might not really be
dehydration, but drinking too much water. Be careful, okay?
(d.) Hyponatremia (Health & Disease Information)
www.hmc.psu.edu/healthinfo/h/hyponatremia.htm
(e.) What is Hyponatremia? www.geo-outdoors.info/hyponatremia.htm
(f.) Hyponatremia - Wikipedia, the free encyclopedia
en.wikipedia.org/wiki/Hyponatremia
(g.) Facts on Hyponatremia www.honoluluclub.com/pulse.php?ID=31
(h.) Drink Water!
www.MensHealth.com/cda/article/0,2823,s1-1-0-0-1558,00.html
Let water work for you
It's warm now, so remember: Your muscles need H2O to work at peak efficiency.
Plan ahead-- by the time your brain tells you you're thirsty, your body's fluids
are depleted, says Larry Kenney, Ph.D., president of the American College of
Sports Medicine. Everyone sweats at a different rate, based on heredity, fitness
level, and degree of acclimatization to surroundings.
Drinking
Start drinking water at least 15 minutes before beginning your activity. The
rule of thumb is to drink 8 ounces of water for every 20 minutes of exercise.
Where it Goes (in descending amounts)
1. Urine
2. Sweat
3. Evaporation (other than sweat)
4. Metabolic processes (water used inside the body) and respiration (water lost
while exhaling). Both are negligible amounts compared with the first three
Your Sweat rate
Weigh yourself before and after a workout, and subtract the weight of any water
you drank while exercising. If the before-and-after difference is . . .
* 2 percent of your body weight, your athletic performance suffered.
* 3 to 4 percent of your body weight, there are potential health risks,
including elevated heart rate and body temperature.
Refueling Rule
For every pound of body weight you've lost during the workout, drink 16 ounces
of water. Then remember that guideline for your next workout. So if you're 2
pounds lighter after an hour-long run, drink 32 ounces more before or during
your next run. Sound like more than you can swallow? Kenney says some people
find that they can drink more of a sports drink than of water.
The Urine Test
If your urine looks more like iced tea than lemonade, you're dehydrated. The
closer to clear, the better.
Related Articles:
* 5 Ways to Add More Fiber
* 5 Abs Building Tricks
* Get Milk (and lose body fat)