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  1. #1
    The Rabbi seely's Avatar
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    What does potassium do?

    I always hear about potassium, but I have no idea if its a good thing before/during/after excercise, if its terrible and makes you cramp, or what. I just hear it mentioned every now and again it seems. I know when I ride though theres always a few bananas in my pockets (insert 3rd grade jokes here) and I am wondering if its good or bad to be eating a lot of potassium? If its good, when does it do the most good? Before or after a ride?

    Thanks
    Jon

  2. #2
    Just ride. roadbuzz's Avatar
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    It's good, and a shortage can contribute to muscular fatigue and cramping. You should get potassium in proportion to sodium. I'm not sure, but 2:1 sodium to potassium comes to mind. Since sodium (read 'salt') is added generously to most processed food, it's darn near impossible to overdo potassium. In general, it actually isn't as important to get before, during, or after riding, as mainly sodium is lost in perspiration. Potassium isn't taken into the cells as easily as sodium, so it's more important to just make sure getting it in your regular diet.

  3. #3
    BLOWOUT!
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    I am not 100% sure but I remember my highschool xc coach saying that potassium is commonly blamed for cramps. This is true. The gassy kind of cramps. Not muscle cramps like most people would think. Don't quote me on it and look into but highschool wasn't that long ago.

  4. #4
    Science Fanboy KrisPistofferson's Avatar
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    It's very important for your muscles, and like calcium, you have to pay specific attention to your diet to get enough of it. I've gotten deficient in it before, and it's kind of horrific to look down at your calf and think, "Who put that baseball in there?" The cramps can be EXTREMELY painful.

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    potassium is an electrolyte that helps to control proper muscle function, both skeletal and cardiac, used in the transmission of nerve impulses and helps to regulate the release of insulin into the bloodstream and it is actually more abundant in the cells of your body than sodium (sodium is more present in your blood stream). Foods that are rich in it include bananas, beef, avacados and most green veggies. Drink plenty of water with exercise to combat dehydration as well as something like gatorade to help replace lost electrolytes.

  6. #6
    Senior Member miamijim's Avatar
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    Potassium cause muscle relaxation. Not enough and muscles tend to stay contracted (cramping). Calcium cause muscle contraction.

    When prisoners are executed via lethal injection high doses of potassium are injected IV. This high concentration cause the heart to arrest in diastole (a relaxed state). This is what I do everyday for a living except its in an operating room during open heart surgery.

    Eat a balanced diet, replace your electrolytes when you sweat alot and you'll do fine.
    WWW.CYCLESPEUGEOT.COM 2005 Pinarello Dogma; 1991 Paramount PDG 70 Mtb; 1976? AD Vent Noir; 1989 LeMond Maillot Juane F&F; 1993? Basso GAP F&F; 1989 Terry Symmetry; 2003 Trek 4700 Mtb; 1983 Vitus 979

  7. #7
    Senior Member stric's Avatar
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    Bananas are known to have some of the highest amounts of Ka in any food. In addition they are also a nice source of carbs. No wonder they still are one of my favorite foods whenever I ride.
    Remeber, you nid, Ca, Ka for your muscles. You also need fats, carbs and so on. Avoid soda and coffee; they dehydrate you and that can cause some unexpected cramps. Drink lots of water but not too much. Too much water will wash our healthy nutrients from your system more quickly.

  8. #8
    Senior Member FXjohn's Avatar
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    Quote Originally Posted by stric
    Bananas are known to have some of the highest amounts of Ka in any food. In addition they are also a nice source of carbs. No wonder they still are one of my favorite foods whenever I ride.
    Remeber, you nid, Ca, Ka for your muscles. You also need fats, carbs and so on. Avoid soda and coffee; they dehydrate you and that can cause some unexpected cramps. Drink lots of water but not too much. Too much water will wash our healthy nutrients from your system more quickly.
    I beg to differ

    Coffee and Dehydration--Urban Myth
    The logic goes like this: Diuretics cause dehydration. Caffeine is a diuretic. Coffee contains caffeine. Hence drinking coffee causes dehydration. The flaw in this logic is that coffee is NOT mostly caffeine, it is mostly water. The water provides hydration, while the small amount of caffeine has negligible or no effect. Many studies have shattered the myth about coffee and dehydration, but a recent thread in the newsgroup aus.bicycles showed that the scientific evidence apparently has not have reached everyone. Again, note the importance of distinguishing between the beverage of coffee, and the substance of caffeine; the small amount of caffeine in coffee is a diuretic, but it does not somehow eliminate the hydration effect of the large amount of water, or, according to several of the studies, diminish it at all. It is a shame that some people are giving up all the health benefits of coffee based on an urban myth. There are too many studies to list them all, but I've included some of them below.

    http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract
    Investigations comparing caffeine (100-680 mg) to water or placebo seldom found a statistical difference in urine volume. In the 10 studies reviewed, consumption of a CB resulted in 0-84% retention of the initial volume ingested, whereas consumption of water resulted in 0-81% retention.

    Wow, now it looks like caffeine increases hydration!


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    http://www.diet-coaching.com/QOMMay2.html
    Q - Iíve heard that drinking tea and coffee is bad for you as they promote dehydration and so should be avoided by athletes as they harm performance. Is this true?

    A - I commonly hear this question asked and the usual reply, by a well meaning person, is that tea and coffee are diuretics (lead to body water loss), contain Ďtoxinsí or that you have to drink equivalent volume of water to counteract their water-losing effects. If this were true, Great Britain would be holding fewer medals at World and Olympic level! Sometimes dietary advice persists in nutrition based on anecdotal evidence, voodoo science and myth. Conclusions are drawn on topics that seem Ďobviousí or logical and yet have not been subjected to the rigor of scientific appraisal. Professor Ron Maughan and accredited sports dietitian, Jane Griffin, recently reviewed the scientific evidence to look at the commonly held view that tea is a diuretic and that that normal tea drinking habits are associated with poor fluid balance.

    The bottom line is that there is no evidence base in the scientific and medical literature for the commonly quoted idea that all caffeine-containing drinks should be avoided in situations where fluid balance is, or might become a problem.


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    http://www.flp-aloevera.co.uk/water_benefits.htm
    The way it's almost always stated, in books, magazines and newspapers, the 8-by-8 rule specifically discounts caffeineated beverages, such as coffee. This is flat wrong. Caffeine does cause a loss of water, but only a fraction of what you're adding by drinking the beverage. In people who don't regularly consume caffeine, for example, researchers say that a cup of java actually adds about two-thirds the amount of hydrating fluid that's in a cup of water.


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    http://content.health.msn.com/conten...cle/1668.51096
    "For years, newspaper and magazine articles have repeated the notion that caffeine is dehydrating as if it's absolute fact," says University of Nebraska researcher Ann Grandjean, EdD. But in a study published in the October 2000 Journal of the American College of Nutrition, Grandjean and her colleagues at the Center for Human Nutrition showed that it's pure fantasy.

    The researchers looked at how different combinations of water, coffee, and caffeineated colas affected hydration levels in a group of 18 men between the ages of 24 and 39. During one phase of the experiment, the only fluid the volunteers consumed was water. During another, 75% of their intake was caffeineated.

    "Using almost every test ever devised to measure dehydration, we found no difference at all," says Grandjean.

    The full study can be found at: http://www.jacn.org/cgi/reprint/19/5/591.pdf


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    http://www.gatech.edu/news-room/arch...ptenmyths.html
    "Recent research points toward the equivalent of about two or three cups of caffeineated beverages having little or no diuretic effect."


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    http://www.minnesotagardener.com/arc...ons/000209.htm
    Unfortunately, the hydration issue got wrapped up in other issues like sugar content, aspartame side affects, phosphoric acid vs. bone calcium and caffeine; valid issues but nothing to do with hydration. Caffeine is another debunked issue. The old argument was that caffeine is a diuretic so it defeats the hydration. Recent studies have shown, however, that its diuretic effect is much less than previously thought and people who regularly drink caffeineated drinks show little affects from it. I know thatís true for me. An excerpt from the drKoop.com web site:

    In the newer study, 18 healthy young men drank either water alone or water plus other beverages including coffee and caffeineated colas in assorted combinations. The researchers found that urine volumes had not varied according to whether the subjects had consumed caffeineated or non-caffeineated beverages. They said the reason their findings differed from those of the earlier study was probably that their subjects had regularly consumed caffeineated beverages daily until the experiment. Other investigators have likewise suggested that the body adapts to caffeine intake so that eventually it has little or no effect on water losses.


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    http://www.globalpinoy.com/pinoyheal...th_fitness.htm
    But studies like the one published in the 2000 Journal of the American College of Nutrition found that if you are a habitual coffee drinker, you retain practically all the liquid in every cup of coffee you drink because your body has adjusted to the slight diuretic effect of caffeine.

    If you are not used to drinking coffee, your body will retain only two-thirds of every cup you drink but this is a far cry from the negative fluid loss that once was believed. Other studies have found that two to three cups of coffee a day has little effect on dehydration but six cups or more will lead to a 3 percent loss of body water.

    Alcohol, meanwhile, is truly dehydrating because the body needs water for your liver to metabolize all that tequila you just drank. However, studies found that one drink won't harm you and diluted alcoholic drinks like beer can count as a fluid replacement as long as you drink moderately.


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    http://www.scienceagogo.com/news/200...runc_sys.shtml
    Finally, strong evidence now indicates that not all of the prescribed fluid need be in the form of water. Careful peer-reviewed experiments have shown that caffeineated drinks should indeed count toward the daily fluid intake in the vast majority of persons. To a lesser extent, the same probably can be said for dilute alcoholic beverages, such as beer, if taken in moderation.


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    http://www.cnn.com/2002/HEALTH/diet....en.water.otsc/
    We've all heard that caffeine is dehydrating. However, we've talked to a couple of experts who point to studies that say, you know what, when we look at it, people get just as hydrated from caffeineated beverages as they do from decaffeinated beverages. So of course you don't want to drink just caffeineated beverages all day, but if you have a cup of coffee in the morning and a cup of tea in the afternoon, you can count that as some of your water -- some of your water intake.


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    http://abcnews.go.com/sections/livin...health_10.html
    Myth: Drinking coffee, caffeinated drinks or alcohol in hot weather causes you to lose extra fluid. Coffee's not the best bet for a hot day, but it won't dehydrate you.

    People buy into this one because caffeine-spiked drinks are diuretics ó hey tend to make you urinate. But drinking a cold Coke or an iced cappuccino wonít cause you to pee out much more than drinking the same amount of water. Just go easy on the frosty six-packs; alcohol has a much stronger diuretic effect than coffee or cola. Sports drinks and beverages that contain sodium are your best bets for hydration on a hot day, because sodium helps your body retain fluid.


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    Hopefully the myth of coffee and dehydration will someday die, but I'm not holding my breath. There are a lot of well-intentioned, but ignorant, people that are intent on perpetuating it.

  9. #9
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    Quote Originally Posted by stric
    Bananas are known to have some of the highest amounts of Ka in any food. In addition they are also a nice source of carbs. No wonder they still are one of my favorite foods whenever I ride.
    Remeber, you nid, Ca, Ka for your muscles. You also need fats, carbs and so on. Avoid soda and coffee; they dehydrate you and that can cause some unexpected cramps. Drink lots of water but not too much. Too much water will wash our healthy nutrients from your system more quickly.
    potassium is K. Ka is not an element.

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