Electrolytes serve three general functions in the body:
many are essential minerals
they control osmosis of water between body compartments
they help maintain the acid-base balance required for normal cellular activities
The sweat that evaporates from the skin contains a variety of electrolytes. The electrolyte composition of sweat is variable but comprises of the following components:
The ideal sports drink will contain the correct ratio of electrolytes, B-complex, chromium, branched chain amino acids, with very low salt (sodium) and may or may not contain protein. Debate continues as to whether or not sports drinks should contain protein. New research suggests there are benefits from having protein in sports drinks. To read more on this click here
The three main electrolytes are sodium, potassium and chloride.
Americans already take in up to 5 grams of sodium daily in their diet, which is ten times the amount required. We definitely do not need more sodium. So, salt tablets and salt-supplements are contraindicated for the majority of athletes. The only effect of using salt tablets and salt-laden (sodium) sports drinks is reduced sports performance.
Serum sodium levels are rigorously controlled by the body and adding unnecessary sodium will only impair performance. Excess salt causes edema (retention of water), which is the last thing an athlete needs. It slows you down. The only sodium you want in a sports drink is the amount needed to balance the other electrolytes.
Only Ironman-type athletes (100-mile distances) need sodium. Athletes running three hours or less need waterand carbohydrates – but not sodium. Our bodies were designed to perform well with the amount of sodium found in natural food, not packaged food. Following the ratios of potassium to sodium as dictated by nature is always sound. Even African long-distance runners, the finest runners in the world, perform at maximum capacity with a low sodium diet. But they cannot perform in a low potassium environment.
Potassium is the most important component of a properly made sports drink. Human cells contain more potassium than any other mineral. Potassium converts glucose into glycogen for storage and later use. It’s also essential to muscle contraction, hormone secretion, and nerve transmission. Unlike sodium, most Americans do not get enough potassium in their diet.
Average potassium intake in the U.S. is 2,500 mg per day while the minimum recommended is 3,500 mg per day. 3,500 mg of potassium per day relates to non-exercising, inert humans. If you think you are getting enough potassium in your diet, you may be surprised to find that even the best diet is often lacking in bioavailable potassium.
A top sports nutritionist comments: A Human Maximum Performance client of mine, who is a professional athlete, keeps a rigid daily diary of foods consumed, as required for the program. When I informed him that his potassium levels were low, and that was why he was so tired after running his usual ten miles, he looked at me in horror and said, “No way! I eat plenty of potassium-rich foods.” “Yes, you do,” I responded, “but you are cooking these foods which removes about 50% of the original potassium content.”
The athlete uses potassium at an accelerated rate so his requirements are higher than that of the average person. Potassium deficit can stop an athlete in his/her tracks because potassium is lost in sweat and hemolysis. Loss of blood cell potassium is a serious matter, especially for the athlete. Even top athletes lose their edge as soon as potassium stores drop too low. Recommended potassium intake viewed as safe and adequate is 1,875 mg to 5,625 mg daily.
Legal limits on potassium in tablets and capsules are 100 mg. Tablets and capsules of potassium are not recommended for a myriad of reasons – the main one is that most potassium supplements do not contain balanced electrolytes as required by athletes, and athletes would need to take handfuls of tablets or capsules to get adequate amounts of potassium.
It is far better to get the extra potassium needed during exercise from your food supply (fish, poultry, low glycemic fruits and vegetables) and from your sports drink. Ideal levels of potassium in a sports drink are 200-250 mg of potassium per 16 ounces of drink. Keep track of the amount of potassium you are taking in from your multi-vitamins, vitamin supplements, protein milkshakes, meal replacements, and sports drinks combined. Do not ingest more than about 3,000 mg of supplemental potassium per day and do not take potassium without carbohydrates or food. People with kidney failure need medical advice before using potassium supplements or eating potassium-rich foods.
Chloride works synergistically with sodium and potassium. It controls electrolyte and fluid balance. Table salt (sodium chloride) is made up of sodium and chloride. Since Americans ingest too much salt, they also get too much chloride. Chloride is found in many sports drinks because it is an integral part of natural ingredients (carbohydrates). In a sports drink, the acceptable level of chloride should be less than 100 mg per 16 ounces of sports drink.
Optimum Electrolyte Ratios
(per 16 ounces of liquid)
Potassium 200-250 mg
Sodium 45-55 mg
Calcium 60-80 mg
Magnesium 18-25 mg
Chloride 60-85 mg