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Dr of Golf
07-31-2003, 05:52 PM
Here's an interesting read from MEDSCAPE Physician's News. Thought I'd share! :)


Too Many Fluids as Bad as Too Few
By: Daniel J. DeNoon
Reviewed by: Gary D. Vogin, MD


July 18, 2003 - For water and for sports drinks, the new message is to drink wisely. Too many fluids are at least as dangerous as too few, according to an editorial in the July 19 issue of the BMJ. But even though the USA Track & Field association changed its guidelines in April, the word hasn't reached everyone.

Most people still think you're supposed to drink as much as you can. But that advice is dead wrong, said Timothy David Noakes, MD, PhD, author of the editorial and chair of exercise and sports science at the University of Cape Town and the Sports Science Institute of South Africa. An authority on endurance sports, Dr. Noakes advises South Africa's national rugby and cricket teams. He's also the author of Lore of Running, for years a bible to many serious runners.

"People have been coached to think that dehydration is the worst thing that can happen during exercise, so now you have a dangerous situation," Dr. Noakes told Medscape. "A woman only needs to put on 2.5 kg of fluid to kill herself. It adds up real quickly - it is easy to get overloaded. It is frightening how easily it can happen."

Dr. Noakes explained that for a 70 kg man at rest, the kidney passes only about 1 liter of water per hour. If you combine that with a similar amount of sweat, that's 2 liters per hour of water loss. However, while walking or running, sweat rates go down to about 300 mL per hour and urine production also diminishes during exercise. The situation is worse for women.

It's often said that by the time you get thirsty, you've waited too long to take a drink. Nonsense, Dr. Noakes said.

"The idea that thirst comes too late is a marketing ploy of the sports drink industry," Dr. Noakes said. "They tell people their thirst is not giving them right information. There is absolutely no biological information that is correct. The answer is just drink what your thirst dictates."

The Beginning of Bad Advice

In his editorial, Dr. Noakes notes that from ancient times until 1969, people didn't drink during exercise. Then an influential - and, Noakes says, error-filled - scientific paper concluded that this led to dangerous overheating. Soon after, the first sports drinks hit the market, and advertising encouraged people to drink all the fluids they could.

That still wasn't a problem, until amateur running became popular. Elite athletes don't have time to drink too much. But it's a different story when people run/walk marathons over five hours.

"They are running so slowly they can drink all they want," Dr. Noakes said. "There is no place outside of a pub where fluids are so available as in a marathon in the U.S. And unlike a pub, you aren't limited by having to pay for it. It doesn't take much to get fluid overload."

Between the Rock of Fluid Overload and the Hard Place of Dehydration

Fluid overload leads to hyponatremia, which can result in brain swelling in extreme cases. The swollen brain can lead to seizures and eventually respiratory arrest. This is what killed a woman during the 2002 Boston Marathon.

"Humans are actually designed quite well for dehydration," Dr. Noakes said. "There is very little evidence it has any effect until one becomes very dehydrated - by which time your mouth is so dry, and you have such extreme thirst, that this would never happen. You are going to find water or a sports drink. There is no way you will be seriously dehydrated when you start a race."

Not everyone goes quite so far. Other experts who spoke with Medscape agree that it's terribly dangerous to drink too much water or too many sports drinks. But they are uneasy about dehydration.

The U.S. Track & Field association Web site carries advice from both Dr. Noakes and Douglas J. Casa, PhD. Dr. Casa is director of athletic training education at the University of Connecticut.

"I'd bet many more people running Atlanta's Peachtree Road Race were dehydrated than overhydrated," Dr. Casa told WebMD. "I am not downplaying hyponatremia. But the advice of don't drink the water is not good advice for soccer and football players and runners who are out there sweating."

Dr. Casa stresses appropriate fluid replacement. So does Leslie Bonci, MPH, RD, director of sports nutrition at the University of Pittsburgh Medical Center. Bonci is the nutritional consultant for the Pittsburgh Steelers and Panthers as well as for the Pittsburgh Ballet Theatre.

"It is not one size fits all," Bonci told Medscape. "Each and every person doesn't need same amount of fluids. Not every body has the same sweat rate, the same sodium loss rate."

Safe Use of Water and Sports Drinks

So how much should people drink? "The solution is not to drown oneself," Bonci says. "Water alone is not going to be the best recommendation. You also need something with some carbohydrate and some electrolyte in it. So water alone during exercise, no. Drinking until you slosh or drown, no. The guidelines are 20 ounces of fluid before exercise, and over the course of every hour of exercise drink between 28 to 40 ounces of fluid. That is not enormous quantities."

Dr. Casa has a simple rule. The next time you set out to exercise, weigh yourself before going out. When you get back, step on the scale again. If you lost weight, you should drink more the next time. If you gained weight, you should drink less.

How much more or less? It's easy if you have a metric scale. For every kilogram you lose (or gain) during exercise, you need a liter more (or less) fluid. If you don't have a metric scale, it's one liter of fluid per 2.2 pounds.

And don't forget salt, Bonci notes. It's also a good idea to know your individual rate of salt loss. That can only be measured in a sports clinic. But there's an easy way to tell if you lose a lot of salt when you work out.

"Some people are truly greater salt losers than others," Bonci says. "Those whose sweat stings their eyes, those who get that crust on the skin, should not put all their faith in sports drinks. Their salt should be from food. Those who lose salt have to be more vigilant about adding maybe some extra soy sauce to their meal the night before. And they have to be careful about not overdoing it on fluids."

Mic Soloist
07-31-2003, 08:45 PM
damn.... you can't win

I had like 4 16oz bottles of water while lifting and running the other day in less than an hour. I'm still alive.

I wonder how much is really to much. I try to have at least a bottle of water every 1.5 hours of every day. I don't always but I try.

How much do ya'll drink?

Does this go for beer?


-peace-

Stabber
07-31-2003, 10:36 PM
this is bs. Sounds like the dr had a bad experience with the Culligan man and decided to get revenge

AndresC
08-01-2003, 01:13 AM
Intresting read. I find it hard to drink that much water but i'm sure some do it.

OT but this is me "Those whose sweat stings their eyes" Drips right off my eyebrow into my eye and oh god how it burns.

aka23
08-01-2003, 10:11 AM
Originally posted by Stabber
this is bs. Sounds like the dr had a bad experience with the Culligan man and decided to get revenge

Who is the Culligan man?

Hyponatremia is a real problem and a serious problem, although you probably do not need to worry about it unless you are an endurance athlete (multiple hour events). I expect that the typical person on this site would be more far morely to have dehydration related issues than hyponatremia. Hyponatremia is usually associated with non-elite participants in marathons, ultramarathons, or other extremely long events. They sweat at slower rates than other runners, yet drink larger amounts of fluid. Electrolyte balance also is an important factor.

I have Dr. Noake's book "Lore of Running." It involves a more detailed analysis than I have ever seen of fluid intake, performance, overheating, etc. His assertions are backed up with studies, some of which he did himself. A quick seach on Pubmed found the following:

http://bmj.com/cgi/content/full/327/7407/113
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=4021781&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1299494&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12831696&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11476407&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10695851&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10378907&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2355812&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1925187&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10798796&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12480801&dopt=Abstract

J450n
08-01-2003, 11:10 AM
Lose- lose situation... goes for most things - "Hey, have loads of 'this' it's good for you... Oh no, wait it's bad, or 'your having too much'.. But wait, now 'your not having enough'..... 'Me - I tell you what..... STFU!!!! ;)

Stabber
08-01-2003, 11:15 AM
Originally posted by aka23


Who is the Culligan man?



LOL you dont have the culligan man where you live? Culligan is that company that goes to businesses and refills their water containers and such. They always advertise "call the culligan man" blah blah blah

IronDaddy
08-01-2003, 11:26 AM
I studied this in advanced anatomy and phisiology in high school. While yes, it is true and possible that too much water will cause brain swelling and even death, this is very difficult and usually only seen in situations where individuals have damaged a certain part of their brain that tells them they are thirsty constantly.
The warning is good but probably too extreme.

Sounds like this guy has a personal vendetta against WaterBoy.

aka23
08-01-2003, 11:51 AM
Originally posted by IronDaddy
I studied this in advanced anatomy and phisiology in high school. While yes, it is true and possible that too much water will cause brain swelling and even death, this is very difficult and usually only seen in situations where individuals have damaged a certain part of their brain that tells them they are thirsty constantly.
The warning is good but probably too extreme.

Sounds like this guy has a personal vendetta against WaterBoy.

Hyponatremia is the most common electrolyte disorder in the United States, with an incidence of approximately 1% of hospitalized patients. About half the women studied who finished the New Zealand Ironman triathlon developed hyponatremia, according to a report in the journal Medicine and Science in Sports and Exercise. Hyponatremia means a low concentration of sodium in the blood. Sweating off electrolytes is an important factor, not just fluid intake.

I think the quoted article does not give an accurate view of Dr. Noake's editorial. The full editorial is located at http://bmj.com/cgi/content/full/327/7407/113

Woz
08-03-2003, 02:19 AM
Since cleaning up my diet a few years ago, I noticed that my sweat was no longer salty. I work in construcion doing a lot of digging and lifting etc so I work up a sweat often.

bradley
08-03-2003, 05:28 AM
Originally posted by Woz
Since cleaning up my diet a few years ago, I noticed that my sweat was no longer salty. I work in construcion doing a lot of digging and lifting etc so I work up a sweat often.

The body can also become effecient at sweating. An athlete, for example, may sweat more to keep the body from overheating but the sodium and chloride that is lost in the sweat will be lower than that of an untrained individual. This helps prevent the loss of electrolytes.

mike mcgee
08-20-2009, 08:18 AM
For my job, I've had to take piss tests. I would drink so much water because I wanted to make sure I had to go and would be able to get in and out of there without wasting the day away. Unfortunately, I would feel sluggish the whole rest of the day and have to piss like every 30 mins. I believe you can drink too much and in doing so, flush out many of the nutrients your body needs for performance.

platypus
08-20-2009, 10:34 AM
That article means nothing if you're taking creatine...if I waited until I was thirsty to drink water I'd be in a lot of trouble.