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Sodium/Potassium relationship (Read 924 times)


Marathonmanleto

    Can anyone tell me what the relationship is between sodium and potassium. I recently read an article about an ultra runner who bonked at the end of the Western States 100 because of excessive sodium loss.
    Mile Collector


    Abs of Flabs

      Ooh! That's the sodium/potassium pump. If I remember it correctly from my Cell Biology days, it is used in, amongst other things, transmitting of the signals in nerve cells. The pump accepts 3 sodium ions from within the cell, and using one ATP, transports them out of the cell. It then accepts 2 potassium ions from the outside and transports them into the cell: http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/ion_pump/ionpump.html This creates an electrical gradient (voltage potential). When a nerve cell is ready to fire, it opens up all the sodium/potassium gates, this creates the action potential which sends the signal down a nerve cell. When a person loses too much sodium through sweat, the volt potential cannot be maintained, and the nerves cannot transmit the signals properly. The result is muscle cramping. I've experienced this many times during marathons and very long runs. The cramping almost went away completely after I started taking salt tablets during these long races. Hope this helps.


      Marathonmanleto

        Hey thanks. Not sure about the scientific part, but cramping sure hits home. I have never taken salt tablets in a marathon. How does one know how many and at what point in the race. Doing Detroit at month end and would like to incorporate into my race strategy.
        Mile Collector


        Abs of Flabs

          I was a little light on the scientific part, just enough to relate it back to the cramping problem. When I finish a marathon or a long run (18+ miles), my face is white from the salt. During my first several marathons, there were times when I stood completely motionless in the middle of the road because all 4 muscle groups in my leg locked up completely at the same time. The pain was bad, but nothing unbearable. I'm somewhat weary of taking salt tablets during races because I don't know how much is too much, and what the effects are if I took too much (e.g. would I have a heart attack?) For my last two marathons, I took a Succeed tablet after 1 hour, then every 45 minutes. I completed both of them with minor cramping, but nothing like what I had before. I'm considering taking one at the start, then every 45 minutes to get rid of even the minor cramping/twitching. If you lose a lot of salt, then you should experiment with it. Just remember if you do take salt tablets, make sure they contain potassium too (remember the sodium/potassium pump).


          You'll ruin your knees!

            The finish of WS100 was quite dramatic this year. A young man was about 15 minutes ahead of the next runner when he entered the stadium (Auburn High School) and stepped onto the track. 300 yards from the finish line, more than 99.7 miles on his legs, he collapsed! His legs just quit on him. His pacer helped him to his feet and they staggered toward the finish line. He collapsed several more times before crossing the timing mat and unofficially pronounced the winner. The medics quickly did the once over and loaded him up and took him to the hospital where he remained for the next two days. He was suffering from hyponatremia, which is a substantial loss of sodium. The next morning at the awards ceremony, this brave young man was disqualified for receiving assistance from his crew (tragic, but it was the right call). Sodium and potassium are what we commonly refer to as electrolytes. Over long distances, we sweat these out of our system (ever had a salty film on your body after a long run?). Without these elements, we lose the ability to absorb water through the stomach lining, which results in our taking in less and less fluids. I may not have it exactly right, but I'm not that far off. In many 100 mile races, runners are "weighed" at periodic medical checks. If a runner loses too much weight, he/she is forced to sit and drink until they get back to a critical tolerance of their beginning weight. If they GAIN too much weight, they are forced to sit and take in electolytes/salt, etc to compensate. THIS IS VERY SERIOUS STUFF, hyponatremia is just as dangerous if not more dangerous than de-hydration. And, YES, it is possible to suffer from both at the same time. Hope this helps, be careful out there! Lynn B

            ""...the truth that someday, you will go for your last run. But not today—today you got to run." - Matt Crownover (after Western States)


            Go Pre!

              I feel like a dog when a human talks to it. (blah blah blah blah etc) Is there a guide to go by or should we see a doctor to find out what is best for us to intake during long runs?
              Mile Collector


              Abs of Flabs

                What symptoms are you experiencing? On thing your PCP can help you with is checking your blood pressure. I presume you're considering taking salt supplements during your long runs. If you are susceptible to hypertension, then you should ask your doctor about it.
                  The next morning at the awards ceremony, this brave young man was disqualified for receiving assistance from his crew (tragic, but it was the right call).
                  That sucks.
                  (ever had a salty film on your body after a long run?).
                  What *exactly* does that "salty film" mean? I pretty much always get that pretty severely on any run over 17-18 miles or so. Is it inevitable? Does it mean I'm doing something wrong? If so - which way do I go to fix it (more H20? More sodium?)?
                  E-mail: JakeKnight2002@aol.com
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                  You'll ruin your knees!

                    "That sucks."...yes, it does, but the rules of the race clearly state that a runner cannot recieve any physical assistance whatsoever from his/her pacer/crew. He was very gracious about the race board's decision and has made public statements that they did the right thing...and promised to be back to revenge his loss! AWESOME attitude. The guy that came in behind him (and won it all), was also quite humble about the whole thing. He ran the race of his life and was overjoyed with the fact that he had placed second (and first, by disqualification). As for the hydration/sodium thing...this is a good read. http://www.ultracycling.com/nutrition/hyponatremia2.html I posted it on another thread, but seems appropriate here. You have to experiment a bit with it. Basically, it is OK to have a salty film, that just serves to remind us that we are losing a lot more than water! I have seen all kinds of solutions for this. There are electrolyte capsules you can take to help ensure you are taking in enough. Some brands off the top of my head include Hammer's Endurolytes, S-Caps, and more. There are also lots of drink mixes, Cytomax, Perpetuem, Clip-2, and more, that help with this issue. Don't "sweat" it, just be aware and don't be afraid to try some new things (on your training runs, never try new things at a race...happens all the time with new drinks, gels, etc...that don't sit well and can ruin your race). Good luck with it, Lynn B

                    ""...the truth that someday, you will go for your last run. But not today—today you got to run." - Matt Crownover (after Western States)


                    Marathonmanleto

                      Thanks Lyn B. I read about the WS100 finish. It's what got me thinking about my own experiences with cramps, black toenails and excessive salt film. I have ordered some Suceeed Tablets and plan to try them next weekend on a long run. Great info.
                        What *exactly* does that "salty film" mean? I pretty much always get that pretty severely on any run over 17-18 miles or so. Is it inevitable? Does it mean I'm doing something wrong? If so - which way do I go to fix it (more H20? More sodium?)?
                        "Salty film" is just your sweat, dried. It's nothing bad. It's just that sweat's not pure water. It has a lot of other stuff ... like salt ... in it, which stays behind as the water evaporates.

                        Roads were made for journeys...

                          "Salty film" is just your sweat, dried. It's nothing bad. It's just that sweat's not pure water. It has a lot of other stuff ... like salt ... in it, which stays behind as the water evaporates.
                          Yes, I know how evaporation works. I didn't get a D+ in high school chemistry for nothing. Cool (And, uh, I distinctly remember Mr. Thompson in 10th grade talking about the sodium-potassium pump. But there was this pretty girl in the desk next to me, and ... well, I don't remember anything else about it. I'm with "Daddyo" on this one. Blah blah blah ... huh?) But this "salty film" I'm talking about is more than the usual salty goodness. Somewhere around mile 18-20, something happens. It's most noticable after a marathon, but long training runs do it, too. I end up literally caked in salt. You could scratch it off my face. I'm a big crunchy mess 'o salt. You could have me with a Margarita. And I'm wondering ... is that normal? Am I just a basically salty guy? Or should I have paid more attention to Mr. Thompson in 10th grade? And why are sodium and potassium having a relationship? Do oxygen and hydrogen know about this? How do they feel about it? Shocked
                          E-mail: JakeKnight2002@aol.com
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                            Yes, I know how evaporation works. I didn't get a D+ in high school chemistry for nothing. Cool
                            No offence intended - I guess I just didn't understand your question. Big grin

                            Roads were made for journeys...