u guys have an ironlife membership? they cover this topic here:
http://www.ironlife.com/forum/showthread.php?t=52892
for those who don't.. it just basically states that since there's more sodium than potassium in sports drinks.. u actually hinder your performance if u take in too much sodium.. u need more potassium than sodium for increased expenditure..
and that the high sodium in sports drinks is probably because they want u to buy or consume more of it...
here's the cut and paste for those who wana read the whole thing:
-----------------------
Electrolytes and sports drinks
By Rob Fiagan
The body has a sophisticated system of water/electrolyte regulation governed at the uppermost level by the hypothalamus. By drinking water liberally, you won’t lose nutrients only toxins. (Diuretics, on the other hand, override the body’s regulation system and should definitely be avoided.) The most important factor here is potassium consumption. DO NOT take potassium pills; they are potentially dangerous. Banana is a good source of potassium, and is easier to digest than other fruits or vegetables.
Next time you buy a “performance drink,” take a look at how much sodium versus potassium it contains. If it contains more sodium than potassium, then you are potentially harming your athletic performance. Don’t let millions of advertising dollars fool you, the natural human diet contains much more potassium than sodium (see NHE), whereas the average performance drink contains much more sodium than potassium. Now look at the label on pure orange juice or apple juice; they contain much more potassium than sodium. Who’s right, Mother Nature or the multi-million dollar supplement industry? Dietary anthropology and sports performance research leave no doubt – Mother Nature.
So here’s what you can do to keep potassium levels high: instead of a “performance drink,” create a mixture of 40% apple juice 60% water (or 50/50) and sip it or drink it moderately before and/or during competition. This way blood sugar and insulin levels remain stable, which fosters more constant energy levels and greater access to bodyfat (in addition to sugar) for energy, avoids bloating, and maintains potassium levels. If you want a real-life example of how well this apple-juice/water solution can work, though anecdotal, my brother Rick ran a marathon after having a tumor removed from his knee and he said his energy levels during the marathon were higher throughout the race than in any previous race when drinking the mass-marketed stuff. Let the word go out, to all your teammates and coaches: when tank tops are drenched with sweat late in the fourth quarter, the player with superior hydration and electrolyte status has a substantial, and maybe decisive, competitive advantage.
------------------------------------------------------------------------------------------------------
Because my statements about performance drinks in the Hofstra University letter (reprinted above) run so sharply counter to conventional wisdom and prevailing market forces, I’d like to elaborate so that my assertions will not be dismissed by those who cannot believe that conventional wisdom can be so far off base.
------------------------------------------------------------------------------------------------------
First, the apple juice solution I mentioned in the Hofstra University letter is superior to performance drinks for reasons besides sodium/potassium content. Most commercially marketed performance drinks are essentially inert liquids containing not much other than sodium and sugar. Apple juice, by contrast, not only is rich in potassium and contains little or no sodium but also contains other minerals, such as boron, magnesium, and phosphorus; and antioxidants such as flavonoids and phenols (although a majority of these nutrients/phytonutrients are contained in the pulp and skin of the apple).
Magnesium is particularly important as a catalyst of energy production, and is depleted during exercise. Magnesium interacts closely with potassium in muscle contraction and muscular force output such that if one is deficient or depleted, it adversely affects the other. Gatorade and many other performance drinks contain zero magnesium. Combined with high sodium and low potassium, and loaded with cheap sugar, these drinks are the perfect formulation for sabotaging performance and impeding the effort to win.
Whereas magnesium and potassium work together interdependently inside the cell, potassium and sodium are independently essential antagonists. As explained and illustrated in NHE, potassium is the chief intracellular ion and sodium is the chief extracellular ion. Sodium moves into the cells and potassium moves out via the “sodium-potassium pump” which regulates concentrations of these two electrolytes, thereby maintaining an electrical charge necessary for optimal conduction of neural impulses that prompt muscles to contract. As intense exercises progresses, the concentration of potassium in the blood increases and the concentration in the muscle cells decreases. The opposite happens in relation to sodium.
The more potassium leaves the muscles cells, with sodium entering, the less efficient muscle contraction becomes. Dr. Sejersted from Oslo, Norway reported in a Scandinavian physiology journal article in 1999 that “the decrease in intracellular potassium was linearly related to the fall in maximal force.” Furthermore, potassium is essential for conversion of blood sugar to glycogen. A potassium shortage results in lower levels of glycogen, which can hamper athletic performance. It’s true that electrolytes including sodium are lost in sweat, but as Dr. Michael Colgan points-out (who supplements the diets of the Olympians he trains with potassium but not sodium, and is the author of an excellent book titled, Optimum Sports Nutrition), “your sweat is less salty than you are.” The body conserves electrolytes relative to water, meaning that when competing and sweating, water is what you need most to replenish.
Studies show that generally sodium loss becomes a factor only during vigorous activities lasting more than four hours (like triathalons and ultramarathons) where sweating is profuse. The sales literature put out by the manufacturers of performance drinks in most cases fail to take account of “cellular hydration” which is the most important index of hydration in connection with athletic performance, and which is dependent upon both water and the sodium/potassium ratio. Absent adequate potassium, the only water retention sodium promotes is interstitial, which serves as dead weight to burden and slow-down the athlete. Especially when the average American’s diet, and even that of most athletes, is far too high in sodium and far too low in potassium, the most compelling rationales for producing a drink with three times as much sodium as potassium is for taste and to perpetuate thirst so that more bottles of the product are consumed.
