View Full Version : Clean water can kill
There's an interesting story in today's New York Times claiming that over hydration is more dangerous than dehydration. The article relates to marathoners, but I suspect it would apply equally to long distance hikers, especially those doing long mileage days.
The link is:
http://www.nytimes.com/2005/10/20/sports/othersports/20marathon.html?incamp=article_popular_2
Weary
Whistler
10-20-2005, 14:16
Yeah, this has been known for a while in the professional and science community. Definitely a good thing for the casual athlete to be aware of, though. I think specifically the problem, and root of the word 'hyponatremia,' is low sodium. All that water makes you diluted. The tough thing is that the symptoms are similar to those of dehydration. Tim Noakes has a good exposition of this problem in his book Lore of Running.
-Mark
gsingjane
10-20-2005, 15:27
Runners World magazine did a very interesting story on this a couple of years ago. Apparently an exercise scientist decided to try to discover the clinical basis for the commonly-heard recommendation that people should drink 80 oz. of water per day (the "10 8-oz. glass" idea you hear constantly). He reviewed all the literature and apparently no study has ever been done to substantiate or back this up in any way. What appears to have happened is that the recommendation was made at some point and then just picked up and echo-chambered back endlessly. Most people now believe the "80 oz. rule" to be gospel physiological truth but ... it isn't.
Jane in CT
Yeah, this has been known for a while in the professional and science community. Definitely a good thing for the casual athlete to be aware of, though. I think specifically the problem, and root of the word 'hyponatremia,' is low sodium. All that water makes you diluted. The tough thing is that the symptoms are similar to those of dehydration. Tim Noakes has a good exposition of this problem in his book Lore of Running. -Mark
Here are the key passages from the NYT story:
Dr. Lewis G. Maharam, the medical director for the New York City Marathon and marathons in San Diego, Phoenix, Nashville and Virginia Beach, said he was taking every opportunity this year to educate runners about the biggest threat to their lives on race day - drinking too much water.
..... He knows the danger: in their zeal to avoid becoming dehydrated, runners may end up drinking so much that they dilute their blood. Water rushes into cells, including cells of the brain. The swollen brain cells press against the skull, and the result can be fatal. The resulting condition is known as hyponatremia - too much water.
"There are no reported cases of dehydration causing death in the history of world running," Maharam said. "But there are plenty of cases of people dying of hyponatremia."
Spartan Hiker
10-20-2005, 15:51
W.C. Fields had it right.
You can't trust water: Even a straight stick turns crooked in it.- W.C. Fields
tlbj6142
10-20-2005, 16:09
Given the fact that most hikers have plenty of sodium in their diet, I doubt this is a real concern to hikers.
icemanat95
10-20-2005, 18:13
Yeah, I tend to suck on salted in the shell sunflower seeds while I hike. Plenty of sodium to salt up the gallon or so of water I drink each day while hiking.
jackiebolen
10-20-2005, 18:16
I think if there's anything long-distance hikers have to worry about, it's overhydration and lack of sodium. Most of the hikers I knew were constantly eating ramen noodles and Liptons, which are salty good. Also, I would find it pretty hard to drink too much water when you have to treat it somehow and then carry it up mountains.
Yea, this came up after a runner died following the Boston Marathon a few years ago.
It's rare among long distance runners, and I have not heard of this problem with other endurance sports, including cross country skiing and hiking. The more common problem is dehydration.
gsingjane
10-20-2005, 19:23
Here are some things to think about:
When you need to eat, what signal does your body give you? You get hungry.
When you need to rest, what signal does your body give you? You get sleepy.
When you need fluids, guess what signal your body gives you?
Why should we believe that people are constantly walking around in an under-hydrated or dehydrated state? My kids' track coach told them this with a straight face: that they will have no way of knowing that they need fluids, so they need to drink, drink, and drink some more, because by the time they realize they need to drink, it will be "too late." That's just ridiculous! But standard advice in athletics today!
I can certainly agree that on a hot, sweaty day, people should pay extra attention to making sure they're hydrated. But it is really silly to think that humans would have evolved without a reliable indicator of the need for fluids.
JMHO (and pet peeve!)
Jane in CT
Lone Wolf
10-20-2005, 19:26
I drank about 2 gallons Saturday in 10 hours while running 54 miles. Only peed once.
SGT Rock
10-20-2005, 19:30
Why should we believe that people are constantly walking around in an under-hydrated or dehydrated state? My kids' track coach told them this with a straight face: that they will have no way of knowing that they need fluids, so they need to drink, drink, and drink some more, because by the time they realize they need to drink, it will be "too late." That's just ridiculous! But standard advice in athletics today!
Actually I have heard that for years in the Army. It may be just anecdotal evidence, but: we have more problems with dehydration than over hydration. Too many people are couch potatoes and soda dependent for their hydration. If you don't tell some people to do this before they fall out, they act like they never knew it was coming. I could tell some stories.
So I guess what I am saying is while it may not be totally a true statement, sometimes people (like a coach) may have to say silly things like this to get some people to drink water when they are not used to doing it.
I can certainly agree that on a hot, sweaty day, people should pay extra attention to making sure they're hydrated. But it is really silly to think that humans would have evolved without a reliable indicator of the need for fluids.
JMHO (and pet peeve!)
Jane in CT
Keep up the pet peeve. Hopefully you teach your kids what right looks like. :sun
I think if there's anything long-distance hikers have to worry about, it's overhydration and lack of sodium. Most of the hikers I knew were constantly eating ramen noodles and Liptons, which are salty good. Also, I would find it pretty hard to drink too much water when you have to treat it somehow and then carry it up mountains.
FWIW, Severe symptomatic hyponatremia has been reported in marathon runners and in recreational hikers in the Grand Canyon, according to one medical site that I visited before going to a land trust meeting and returning to eat supper.
Weary
Given the fact that most hikers have plenty of sodium in their diet, I doubt this is a real concern to hikers.
"There are no reported cases of dehydration causing death in the history of world running," Maharam said. "But there are plenty of cases of people dying of hyponatremia."
It really makes sense if you think about osmosis and how being super-hydrated would affect not only your electrolyte systems but also cell turgor, blood pressure, synaptic function etc.
The body is an amazing machine.
tlbj6142
10-21-2005, 09:41
When you need fluids, guess what signal your body gives you?I'm not sure I buy your argument. For one thing there are multiple conditions that can make you feel "thirstly". Sore throat? Allergies? Dry air? You can drink a quart of water and 20 minutes later have a dry throat. Do you really think you need more? I don't think so.
I just pace myself when drinking (and hiking) and ignore the "thirstly" signals as they tend to be false alarms.
Urine color is probably the best indicator. Similar to LW story, I use to work at UPS unloading trucks. In the summer it is crazy hot. I would drink a gallon of water in ~3 hours. Everything on me was soaked with sweat even my leather boots. I would sit down in a plastic lawn chair for our 10 minute break and there would be a puddle under my chair. Yet when I got home, my urine would be slightly yellow. Perfect.
tlbj6142
10-21-2005, 09:43
"There are no reported cases of dehydration causing death in the history of world running," Maharam said. "But there are plenty of cases of people dying of hyponatremia."I don't understand the point of this reply???