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RE: [RC] for those who use electrolytes...help those newbies - heidiI'll summarize what I heard. Some may also be from discussions with Art King. The horse evolved eating feed stuffs with high levels of potassium - grass. Because of that they have developed - those that survived - the ability to dump potassium through the kidney. This is different from humans who developed on a higher sodium diet and that's an important difference when comparing human electrolytes with that required for horses. So far, so good. Would add, however, that the kidneys can regulate their dumping of potassium to some extent, and since it cannot be stored in the bloodstream as such, if excess is present (say, when you pre-load before going to the ride), the kidneys will be in "dump mode." Therefore, when you start adding stress and sweating to the combination (see comments below) you cause even more loss of potassium. If, on the other hand, you arrive at the ride site with kidneys not primed to "dump" potassium, the urinary loss will be minimized. (Note, too, that horses do continue to eat and take in postassium with every bite of forage they consume.) What was discussed was how the electrolytes work in the body at the cellular level and how they are distributed inside/outside the cell. Sodium carries the" message" for the cells to fire. Before the cell fires a large percentage of the ions inside the cell is potassium. Potassium sets the resting threshold potential for cells to fire. After the cells fire there is a large percentage of sodium ions inside the cell. There is a "pump" on each cell that runs off of ATP (energy) that pumps the sodium and the potassium back in. With out a proper balance on sodium and potassium the cells will not function properly. Again, so far so good, at least in relationship to nerves and muscles. And although other cells don't necessarily "fire" they do have a similar intracellular and extracellular milieu. The sodium also plays a role in maintaining the fluid balance in the body which is also related to the blood pressure. The chloride ions provide electrical neutrality. When the body senses a critical loss of sodium it has built in mechanism (the hormone aldosterone) for the kidney to reabsorb sodium ions. This comes at a cost since to maintain electrical neutrality the kidney dumps another positively charged ion - potassium. This in turn impact the sodium/potassium balance required for proper functioning of the cells. Yes, true. But keep in mind the full horse who has a dietary reserve of both sodium and potassium waiting in the hindgut for just that eventuality--that's the way the beast is designed. Aldosterone is a hormone that is also released by stress - hence during stress the kidney is maintaining sodium at the expense of potassium. Again, potassium is the one that the horse replaces most readily by continuing to eat forages, never mind his storage "vat" in the hindgut. Now what does that mean. 1. Horses sweat about the same concentration of electrolytes as in the plasma. Horses have no way or recapturing the ions from their sweat so they lose a lot of electrolytes. Done believe it taste the sweat of a horse. Recapturing the same ions? No, of course not. Instead, they eat new ones continually with their food, in addition to their storage as per the above. 2. Stress is bad. Maybe horses don't physically acclimate (I've never heard of such of a process) to not needing as many electrolytes it is most likely that their stress levels are reduced at a ride instead. Stress hormones would also explain why horses lose more at the beginning of ride when the stress is the highest. No, stress in and of itself is not bad--just TOO MUCH stress is bad. Some stress is necessary to cause adaptation. That's what conditioning does--not just to bones, muscles, etc. but also to metabolic systems. And yes, horses DO adapt--at least to some extent--given the opportunity to do so over time and repetition of the experiences. This also plays a role in selection and is becoming a topic in modern horse breeding--in many of the light horse breeds, modern breeders have selected for a "look" and a particular response in the show ring that is apparently tied into this whole stress/hormonal axis. It has ramifications not only with regard to this subject, but is also being investigated with regard to reproduction, etc. (Hormones tend not to exist in a vacuum--alterations of hormones in one system have an impact on hormones in other systems.) I'll add another comment from personal observation for which I don't have controlled scientific studies to back, just lots and lots of horses at rides--but I suspect that there is a correlation between those horses who have heart rates that don't react adversely to being startled or stimulated and those who don't need e-lytes. Both are reactions to stress. Those horses who constantly jolt themselves with adrenaline tend to be those who spike high pulses when the wind blows a plastic bag through camp and also tend to be those horses who require e-lytes. Would love to be able to design a study to look at such interrelationships--if only there were the $$ for funding... 3. The impact of stress related hormones takes a couple of days to subside so some electrolyte supplementation is necessary for a day a two after the ride. Again, a very individual thing--those horses who don't have a problem to begin with don't need the followup, either. But I'd agree that for those horses that need e-lytes, post-ride e-lyte care makes a lot more sense than pre-ride loading, since the loading will simply set the kidneys up to be in "dump mode" when the horse most needs to conserve. 4. The body is designed to dump excess electrolytes and arrive at the proper balance. The number I have heard by several people is two hours. The electrolytes given two hours ago if not needed are gone. The body does not store electrolytes. Again, depends on how you define "body." Certainly this is true of what e-lytes are in the circulation or have been absorbed into the extracellular or intracellular spaces. But if you include the hindgut as being a part of the "body" (some very precise definitions do say that the gut is "outside" the body in this very sense) then indeed there is considerable storage. So while yes, there is no storage once e-lytes are absorbed (and yes, they are dumped, which once again leads one to question the rationale of pre-loading), it is wrong to assume that one must automatically be sticking directly into the mouth what has just been lost in sweat in order for the horse to maintain the balance, since there IS a considerable reservoir in the hindgut. If the horse did NOT have such a reserve, his balance would be fragile indeed and he would not be very useful as an athlete at much of anything. (Odds are he'd be dead as a species as well.) 5. If you ride 20 miles before you electrolyte you will have a 20 mile imbalance. If you only ride 10 before you electrolyte you will only have a 10 mile imbalance. Imbalance is not good and massive doses that might be required to correct a 20 mile imbalance may not be good - so small doses often rather than large doses not so often. How do you figure? Is his hindgut empty? I should hope not! Indeed, one may see some dips in the e-lyte levels early on due to the hormonal influences you state, but EVEN IF YOU DON'T GIVE EXOGENOUS E-LYTES he will equilibrate again, because he will begin to draw from his hindgut reserves to make up the difference. As the horse settles into the work and the excitement phase wears off, he begins to manage his e-lytes once again without the hormonal drain. And if he continues to eat, all goes along quite normally. I'm talking the normal, healthy horse here that is a) initially suited to his work, b) adequately conditioned to his work, and c) ridden to the level of his suitability and conditioning. 6. Someone I think Angie asked about horses, ulcers and electrolytes. The comments were the are absorber rapidly and in small doses should not be a problem The speaker who is a professor in medical school went on to say in humans ulcers are quite common - in fact about half to two thirds of us are walking around with one but it is only a clinical problem in a small proportion. She didn't see why that was not true in horses so it's not so much the fact that there is an ulcer but the impact of the ulcer. Again small doses often is the better way to go. Small doses, and doses in food. Keep in mind that ulcers are not the only issues. Horses are losing fluids in that sweat as well, and if one gives too many e-lytes in a time frame that the horse cannot or will not make up the fluid deficit that one is causing, one causes dehydration at the tissue level so that the horse can process the e-lytes in the gut. Not a good thing. Additionally, imbalances can occur without careful attention to what e-lytes are going in (and whether those are the ones that should be). And all too often, horses that "hit the wall" due to energy problems instead of e-lyte problems have their problems further compounded by addition of e-lytes that can cause them to further back off of the very eating that they need to make up their energy deficits. (Food of course provides e-lytes AND energy....) Myself I electrolyte often. I will not go over 15 miles - without giving electrolytes. I do not give a full does at one time. On the trail I give a half a dose. In check I have some P&F in the feed (about half a dose)- my horses will gladly eat feed with P&F in it. They are getting electrolytes all during the hold. Then when I go back out I give the other half dose when I go out on trail. I start the day before the horses climb on the trailer with some in the feed. The get some in the feed till they start. Depending on the ride and weather I will preload or not before I start. They get electrolytes in the feed till I get home and then a little in the feed once a day when I get home. You do this automatically without first determining a given horse's needs? Or is this simply your protocol for a given horse, since you indicate below that you have horses with different needs? Again, this is the sort of statement that comes across to newbies as a "have to" sort of statement, when in fact they need to learn a lot more and decide through the course of the conditioning and beginning of competing of their own individual horses if this is something they need to do or not. And it is this sort of "mindset" that we need to be questioning. Such statements need to be prefaced with "I have found that my horse needs blah blah blah," providing of course that you have actually ridden without sufficiently to determine if that IS actually what your horse needs. I will electrolyte after a long hard training ride in hot weather. Well, better than before... But again, as Joe mentioned, you lose some of the training effect by doing so. I did learn that my old mare did not require as much electrolytes as the Jbird. If I am riding in the west I only give about a half to 2/3'rds the amount I give in the east. I still give them as often - just not as much when I give them. If I give the same amount as I give in the east, my horse will sure pee a lot on the trail which is natures way of balancing the system. Well, yes and no. "Nature" is indeed striving to balance--but why imbalance it in the first place? Never mind that it takes more water to dilute all that excess e-lyte out, so you may actually be causing dehydration by "forcing" the need to eliminate all those extra e-lytes. As far as electrolyting a dehydrated horse. If my horse is too dehydrated to be given electrolytes - he/she is too dehydrated to continue so for me it's pretty much a moot point. Oh, absolutely! I agree! However, a dehydrated horse can develop an electrolyte deficiency by drinking a lot of water without being given small doses of electrolytes during the rehydration process. Which is precisely the scenario that is set up by overuse of e-lytes--the horse strives valiantly to get rid of the excess (in order to stay alive) by diluting them sufficiently to pee them out, and then once that equilibrium is maintained, the horse can indeed get into trouble by trying valiantly to replace the lost fluids... Heidi =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ridecamp is a service of Endurance Net, http://www.endurance.net. 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