Electrolyte Replenishment

Edition 7, 2005
By Steve Beaver Born

I've made some big mistakes over the years in vain attempts to resolve heat and electrolyte related problems, from indiscriminately tossing down sodium tablets to guzzling almost every sports drink ever created. For my all-time greatest disaster, I'd choose the 1995 Race Across America. I was in peak physical condition, but I was not prepared for the extreme heat I encountered during the first day through the Mojave Desert. I dehydrated, became electrolyte depleted and ended up in the hospital where they reconstituted me with eight liters of IV fluid! My race across America never made it across California. Just a few hours of inadequate electrolyte and water intake wiped out months of training.

You may never bike through the Mojave in summer, but you will encounter debilitating heat and humidity at some point in your training or competition. However, it doesn't take severe weather stress to prove that electrolytes are as vital to performance as your energy supply.

Even when it's cold outside, and I have a chorus of Nordic skiers to sing "amen" here, you need electrolyte replenishment. Sure, hot weather increases cramping potential, but cramping prevention isn't the primary reason for electrolyte supplementation. No one wants to cramp, of course, but cramping is a place far down the road of electrolyte depletion. Cramping is your body's painful way of saying "Hey! I'm on empty! Re-supply me now or I'm going to stop!" Just as you don't wait until you bonk before you re-fuel, you don't wait for cramps to remind you to take electrolytes.

Electrolytes are analogous to the motor oil in your car—it doesn't make the engine run, but it's absolutely necessary to keep everything running smoothly. Proper functioning of the muscular, digestive, nervous, and cardiac systems depend on adequate electrolyte levels. Cramping is like the oil light on the dash; you never want it to get that low. And when you've got smoke coming from the engine, as I did in the '95 RAAM, your race is over and your day is done.

In this article, we'll look closely at this vital, but oft neglected and misunderstood aspect of fueling. I'll tell you why salt tablets don't work, and why Endurolytes is unquestionably the finest electrolyte formula you can use.

In addition to replenishing calories and fluids, proper fueling during exercise requires consistent and adequate electrolyte support as well. Electrolyte needs vary much more than either caloric or hydration needs, so you may need to need experiment quite a bit in training until you have this aspect of your fueling tailored to your specific requirements under various conditions.

What Are Electrolytes and Why Do I Need Them?

Salt tablets are an unacceptable choice for electrolyte replenishment for two reasons:

  1. They provide only two of the electrolytes your body requires—sodium and chloride.
  2. They can oversupply sodium, overwhelming the body's complex sodium level regulation mechanism.

Each of these issues is important, and we'll discuss both of them. Right now, let's focus primarily on the second one.

Far too many athletes have suffered needlessly with swollen hands and feet from water retention due to ingestion of salt tablets or electrolyte products too high in sodium during prolonged exercise in the heat. The body has very effective mechanisms to regulate and re-circulate sodium from body stores. Excess sodium consumption interferes with or neutralizes these complex mechanisms. Sweat generates large sodium loss, which is monitored closely through hormonal receptors throughout the body. However, rapid sodium replacement neutralizes the system, allowing water intake to dilute sodium content. High sodium electrolyte supplementation contravenes natural physiological serum electrolyte control. Once the body detects an increase in sodium from exogenous sources (i.e., food, salt tablets, or products too high in sodium), the hormone aldosterone signals the kidneys to stop filtering and re-circulating sodium and instead excrete it. When this happens, another hormone, vasopressin, predominates and causes fluid retention. If you've ever finished a workout or race with swollen hands, wrists, feet, or ankles, or if you have experienced puffiness under your eyes and around your cheeks, chances are your sodium/salt intake was too high.

The truth is that the human body needs only a minute amount of sodium to function normally. We require a mere 250 mg of sodium each day, athletes maybe 500 mg, which is easily supplied by natural, unprocessed foods. However, the average American consumes approximately 60007000 mg per day. The average athlete stores at least 8000 mg of dietary sodium in tissues and has these stores available during exercise. In other words, you already have a vast reservoir of sodium available in your body from your diet, ready to serve you during exercise. In addition, your body has a highly complex and efficient way of monitoring and re-circulating sodium back into the blood, which it does to maintain homeostasis. Yes, you do need to replenish sodium during exercise, but it has to be in amounts that cooperate with and not override these complex body mechanisms.

The way to fulfill sodium requirements is not by indiscriminate consumption of salty foods or salt tablets, but rather with a lower-sodium approach that emphasizes a balance of essential minerals that cooperatively enhance the body's natural hormone and enzyme actions. You want a product that contains a moderate supply of sodium, one that will provide necessary electrolyte support without compromising internal regulation.

Don't I Need to Replace What I Sweat Out?

It's easy to formulate a product that matches one of the many perspiration analysis studies and then sell it on the basis that athletes simply need to replace what they lose. Some products do just that. Unfortunately, there's a problem with this because individual sweat-loss differences vary greatly and the human body does not and cannot efficiently replace what it expends during exercise at any intensity above a walking pace. Electrolytes lost are not replaced by electrolytes consumed.

The body replaces only 3545% of what it loses during exercise and this is true for fluids, calories, and electrolytes. If you try to replace all the fluids at once, you may end up with dilutional hyponatremia (overly diluted blood sodium levels) or water-intoxication. If you attempt to replace all the fuel you expend, your stomach will back up in total rebellion, and refueling will grind to a halt. And if you try to replace, in equal amounts, all the electrolytes you lose, a number of hormonal triggers may create all sorts of problems such as gastric distress, edema, muscle spasms, and cramping.

Don't focus on what you lose, but on how much your body can absorb. Endurance nutrition guru Bill Misner, Ph.D., says, "Give it [your body] 3545%, even though it cries aloud for 110%." In regards to the amount of fluids you drink, calories you eat, and electrolytes you replenish, this is an important principle to remember.

So What Is the Answer? How Should I Replenish Electrolytes?

Proper electrolyte replenishment during endurance exercise requires a gradual, consistent approach that incorporates all the electrolytes in amounts that do not override normal body mechanisms. Remember, electrolyte intake needs to be below systemic detection, yet help alleviate systemic depression. This means that you need to consume enough to support body functions and prevent heat-related issues such as cramping without overwhelming your body; electrolyte intake must slip under the body's "radar detection system" while still providing optimal support.

Endurolytes and Endurolytes Powder are full-spectrum electrolyte products designed to fulfill the body's electrolyte requirements, countering the effects of hyperthermia, optimizing specific bodily functions, and enhancing endurance performance, especially beyond the two-hour mark. We do not formulate Endurolytes and Endurolytes Powder to reflect the amounts of electrolyte loss in sweat because each person has a unique biological predisposition in terms of minerals lost via perspiration. Additionally, the differences in an athlete's size and fitness, as well as the pace of exercise, and of course the humidity and heat, can mean up to a 1000% difference when one athlete's sweat rate is compared to another's. A "one size fits all" formula based merely on sweat rates cannot and will not adequately support your specific electrolyte requirements.

In the purest sense, the Endurolytes formula is not so much an electrolyte replacement product, but is better described as an "electrolyte stress support formula." It helps the body perform better under the demands of exercise, especially in heat, by providing a full complement of minerals in the proper balance without interfering with normal body control systems. Endurolytes and Endurolytes Powder work with your body, not against it.

Chelated Minerals and Why Endurolytes Contain Them

Chelation is the process of bonding a mineral to an amino acid, making the mineral more bioavailable. Chelated minerals are the form most often recommended because they provide greater absorption than their non-chelated counterparts. For example, magnesium is 87% absorbed when chelated, but only 16 % when taken in an inorganic, non-chelated form. One nutrition scientist wrote, "Estimates of normal mineral absorption average 10%; however, absorption of chelated minerals may be as high as 60%."

The Endurolytes Formula

Calcium is the most abundant mineral in the human body (about 2.85 pounds in the average person). Normal heart rhythm, healthy nerve transmission, and strong muscle contractions require a constant blood calcium level. During exercise, calcium-dependent enzymes produce energy from fatty and amino acid conversion. Because fatty acids are such an important fuel during endurance exercise, providing 6065% of your energy needs when exercise goes beyond two hours in length, having adequate calcium available to efficiently convert them into energy is crucial. When blood calcium runs low, the body extracts it from the bones, but this process can't keep up with your exercise depletion rate. Serum calcium deficiency during endurance events may produce high blood pressure, muscle cramps, and weakness. 150300 mg/hr is an adequate dose of calcium to maintain the aforementioned physiological functions.

Magnesium should accompany calcium at a ratio of 1:2. When calcium flows into working muscle cells, the muscle contracts; when calcium leaves and magnesium replaces it, the muscle relaxes. Many enzymatic reactions necessary for fuel conversion to muscular energy occur in the presence of adequate magnesium. Deficiency of magnesium contributes to muscle cramps, tremors, sleep disturbances, and in some cases, convulsive disorders. Though 100 mg or more is lost in sweat and used up by the muscles hourly, 75150 mg/hr adequately replenishes magnesium without the laxative effect larger doses can produce.

Potassium is the chief cation (positively charged ion) within all muscle cells, necessary for maintaining the optimal concentration and balance of sodium. Potassium deficiency symptoms are nausea, vomiting, muscle weakness, muscle spasms, cramping, and rapid heart rate. 75150 mg/hr is an adequate replenishment amount. Even though 100200 mg are lost in sweat alone (not counting internal muscle and cell use), if we try to replace it all at once, optimal sodium balance is altered. In addition, too much potassium is hard on the stomach and can cause severe stomach distress.

Sodium is the chief cation (positively charged ion) outside the cell. The average American carries 8000 mg of excess sodium in extracellular tissues. During endurance events, a minimum of three to four hours is necessary to deplete this mineral, which may result in symptoms of abnormal heartbeat, muscle twitching, and hypoventilation. However, if sodium is replaced at the same rate as depletion, it overrides the hormonal regulating mechanisms that enable the body to conserve electrolytes. Consumption of too much sodium will cause a variety of problems, the least of which is fluid retention. Therefore, we highly recommend a more moderate, body-cooperative replenishment of 120240 mg/hr of sodium, as sodium chloride.

Chloride is the relative anion (negatively charged ion) that accompanies sodium. This electrolyte is absolutely necessary in maintaining the osmotic tension in both blood and extracellular fluids. It's a somewhat complicated process, but to put it in the simplest terms, think of osmotic tension as being the proper balance and consistency of body fluids and electrolytes. We believe 180360 mg/hr of chloride (as sodium chloride) adequately replenishes chloride without overriding the function of the hormone aldosterone in regulating and conserving proper electrolyte levels.

Note: "salt" (commonly called "sodium") refers to sodium chloride, which is 40% sodium and 60% chloride by weight. The recommended amounts given above for both electrolytes, sodium and chloride, when combined together equals 300600 mg sodium chloride, our recommended "salt" intake.

Manganese is included in Endurolytes as it is necessary in trace amounts for optimal muscle cell enzyme reactions for conversion of fatty acids and protein into energy. Again, fatty acids and protein are an important, even crucial part of the endurance athlete's fuel supply, so while manganese is not technically an electrolyte, its importance cannot be overstated. Research also shows that manganese deficiency plays a key role in blood sugar fluctuation, free radical build-up from intense exercise, and nerve function disorders, especially in older athletes. Taking 510 mg/hr will help resolve all these issues, hence its inclusion in Endurolytes.

Pyrodoxine HCL (vitamin B-6) is a coenzyme required in 60 enzymatic reactions involving metabolism of carbohydrates, fats, and protein. We include this water-soluble B vitamin in Endurolytes because of its active role in maintaining sodium-potassium balance.

L-Tyrosine is an amino acid added to protect thyroid and adrenal function. Blood plasma deficiency during extreme endurance events will lower thyroid and adrenal production, which hinders the proper rate of metabolism. Symptoms of l-tyrosine depletion first appear as depression, later anger, then despondency that degenerates into total despair. If any of these has ever happened to you during a long training session or race, it may be due to low thyroid and adrenal production; it can be easily avoided by the intake of supplemental l-tyrosine at 50100 mg/hr.

Glycine is an amino acid added to Endurolytes Powder to help neutralize the naturally salty/bitter taste of the minerals.

What About HEED?

HEED is Hammer Nutrition's newest fuel, an all-complex carbohydrate powdered sports drink. One of the nice features of HEED is that it contains a complete and easily assimilated electrolyte profile, not just salt and potassium, which is all you get in most other sports drinks. Two scoops of HEED provide the electrolyte equivalent of approximately 11.25 Endurolytes capsules. Some athletes will find that with a scoop or two of HEED in their water bottle they're good for well over an hour. For other athletes, the electrolyte profile in HEED will provide an excellent base from which additional Endurolytes capsules can be consumed (or Endurolytes Powder can be added to the mix) to completely satisfy electrolyte needs.


Consistent replenishment of fluids and calories is absolutely essential to maintain energy levels during workouts and races. This article has shown you that providing constant replenishment of electrolytes is an equally important component of proper fueling. While getting your fluid and caloric needs dialed in and nailed down is fairly easy to accomplish (especially if you read the related articles in this book), properly fulfilling your electrolyte needs can be a bit more challenging because it's an ever-changing process, dependent on several variables. Using Endurolytes or Endurolytes Powder in your training will resolve that challenge. They contain the right minerals in the right balance, and because they are independent of your caloric and hydration sources, they provide you with the necessary dosage flexibility. Regardless of your size, sport, training intensity, fitness level, or the weather, you can fulfill your electrolytes needs accurately and precisely with Endurolytes or Endurolytes Powder.

Steve Born is a technical advisor for Hammer Nutrition with over a decade of involvement in the health food industry. He has worked with hundreds of athletes—ranging from the recreational athlete to world-class professional athlete—regarding their supplement/fueling program. Steve is a three-time RAAM finisher, the 1994 Furnace Creek 508 Champion, 1999 runner-up, the only cyclist in history to complete a Double Furnace Creek 508, and is the holder of two Ultra Marathon Cycling records. In February 2004 Steve was inducted into the Ultra Marathon Cycling Hall of Fame.

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