Quote
herosemblem
Quote
Frank Furter
Quote
plawrence
Quote
SoCalCPA
Good one Eeek - I deserve it - but seriously, whenever I superhydrate the night before, it makes a big difference for me when doing something strenuous the next day - Maybe it's on "old wives" tale kind of rememdy but it sure seems to work for me.
If you're going to superhydrate yourself the night before by drinking a lot of water, the key to not having to make multiple runs to the bathroom during the night is not to eat (or drink) anything sweet. If you drink a lot of fluid and also consume sweets (either in solid or liquid form), you are much more likely to release the water during the night (which kinda defeats the point of hydrating yourself the night before).
OTOH, eating a few salty nuts with the water the night before will help your body retain the water.
Do you understand glucose metabolism, serum osmolality, anti-diuretic hormone, glomerular filtration, water homeostasis, congestive heart failure, natriuretic peptide, the autonomic nervous system and body fluid volumes well enough to
be making these sort of broad recommendations?
"Be making"?
How about simply saying "make"?
Incorrect: "You shouldn't
be do
ing that."
Correct: "You shouldn't do that."
It isn't necessary to add "be" & "ing".
I agree on the salty nuts/retaining water sentiment. Experience demonstrates this. No need to use fancy words and claims, just to make oneself feel more intelligent.
If you are commenting about an infinitive and gerund combination, it is perfectly correct grammar. It may not be the finest diction and Strunk (Elements of Style) may object to the word choice and wordiness, but it is not technically incorrect to my knowledge.
The argument presented seems to be that eating peanuts will reduce the amount of water you need to drink the next day or in some beneficial way, to hold on to more water that can be used for sweat on the trail. Peanuts are a fine and wonderful food, however, they do not substitute for adequate water intake any more than sea water does. If a person drinks sea water, for example, that "volume" of salt water will have to be diluted to a physiologic concentration by water in that person's body--- the seawater will, in effect, steal fluid that could be used for sweat production.
Sweat and other insensible water losses (humidified exhaled air, for example) are primarily fluids with very low electrolytes concentration. To create sweat, water is moved from extracellular and intracellular fluid spaces into eccrine sweat glands. Eventually, as more and more water is lost by sweat, the electrolyte concentrations of sodium in the extracellular fluid rise (because more water than salt is lost). This rise in sodium (hypernatremia) stimulates the release of anti-diuretic hormone (ADH) from the pituitary which acts on the kidneys to make the urine very concentrated (thus holding on to more water). As increasing water loss (dehydration) occurs, the reduction of the extracellular and intracellular spaces eventually causes a decrease in circulating blood volume (one explanation for an increase in heart rate with severe dehydration). With extreme dehydration and reduction in blood volume, additional compensatory body responses occur beyond tachycardia.
It is not really possible to load with salt to "expand" the extracellular space with salt + water to produce a situation beneficial to sweat production because it will essentially eventually result in too much salt in the body. Sweat production does not depend upon salt availability so much as upon water in the body. In excess and in chronic conditions, added sodium becomes a problem because it can expand abnormally the extracellular space which can result in abnormally swollen tissues, hypertension or high sodium concentration in the blood. However, in most normal healthy individuals expanding the extracellular fluids is a benign event to which the body can compensate. Sodium chloride primarily stays in the extracellular fluid space and since sweat does not contain much sodium chloride, not much sodium is lost when sweat is produced. If I remember correctly, there is even some reabsorption of salt by the skin which means that the net salt loss is low and easily met by dietary intake. The body does not really have a way to store "pure water" very well. Eventually, excess salt is removed by the kidney, obligating the production of urine to eliminate those electrolytes.
The normally functioning kidney filters into the nephrons (functional unit of the kidney) about 6 liters of fluid per hour. Obviously this does not all become the 30-100 ml of urine most people make per hour. Therefore, most of the kidney's job is to recapture the filtered fluid. When you drink pure water, it causes a drop in serum osmolality (which is mainly related to the sodium content) which then inhibits ADH production. Very quickly the kidneys stop re-absorbing fluid and produce a very dilute urine. So for most people, "tanking" up or "water loading" the day before will just result in more trips to the bathroom before reaching the trailhead because the body does not understand that it is suppose to store that fluid for future sweat production. There is no value to adding excess salt to someone on a typical American diet, because we already have more salt than we need. If you tank up with lots of salt and water, you will not urinate so much because your osmolality (a trigger for ADH) will not change as much, but the body will not have the "low salt fluid" that is desirable for sweat production and will eventually have a burden of salt to eliminate. The goal should be to match acutely your water intake to your water losses.
My personal approach is to drink 16-20 oz just before hitting the trail so that there is less to carry and less loss into urine and to drink frequent 4-8 oz volumes on the trail depending upon conditions. There are certain gastrointestinal and kidney diseases or hormonal problems (like Addisions Disease) that may benefit from sodium loading because there is a chronic loss of sodium, but there is no value to the normal person for the purpose of preparing for strenuous activity to add salt beyond what is in a normal diet (since the normal American diet has an excess of salt to begin with). For most people under typical conditions, the best hydration fluid is water alone without added salt in sufficient volume to result in production of about 500 ml urine/ day.
The cure for a fallacious argument is a better argument, not the suppression of ideas.
-- Carl SaganEdited 1 time(s). Last edit at 08/03/2011 05:15PM by Frank Furter.