Charging up With Electrolytes

Energy, strength and stamina are composites of true health and lasting performance.

As the science of sports nutrition continues to evolve, thousands of active men and women are slowly but surely developing an understanding of biological medicine, optimum nutrition and the intelligent use of dietary supplements.

Understanding water and its effect on exercise performance is crucial. During strenuous or prolonged physical activity, the water content of all body compartments decreases as fluid is lost through sweating and insensible water loss from the lungs, especially at high altitudes. A two per cent loss of body weight through water loss can greatly reduce exercise capacity. That’s why everyone who works out or plays any sport needs to prehydrate, hydrate and rehydrate with filtered, clean pure water.

I have traveled from Victoria to St John’s, testing the body composition of thousands of Canadians–young and old, active and sedentary. Using a method known as bioelectrical impedance, I calculate the percentage of lean mass, body fat and water in each individual, and determine the individual’s ratio of lean mass to fat. As men and women age, they lose muscle, gain fat and slowly dehydrate. The only exceptions to this rule (regardless of age) are those who incorporate strength training, aerobics and plenty of water into their lifestyle.

Electro-What?

Electrolytes are defined as inorganic salts (acid or base) dissolved in both cellular and extracellular fluid. Important electrolytes include potassium, magnesium, phosphate, sulfate, bicarbonate, sodium, chloride and hydrogen.

Electrolytes carry both negative and positive electrical charges which affect the bioelectrical status of cells. They regulate intracellular fluid volume and control the pH of cells. pH is the symbol for "potence hydrogen" and refers to the acidity of a solution. pH is measured on a scale between zero and 14, with numbers below seven referring to acid, and numbers above seven referring to alkaline or base. The pH of blood is carefully maintained at a constant alkaline pH between 7.35 and 7.45. Human saliva ranges between 6.35 and 6.85, whereas the gastric juice of the stomach has a pH value of 1.2-3.0. The ideal range for muscle is 6.9-7.0.

Electrolytes modulate fluid exchange within various compartments. This regulates a constant exchange of nutrients and waste products between the cell and its external fluid environment. Electrolytes affect nerve transmission, muscle action and gland function. They also maintain the permeability of the plasma membrane and regulate the acid and base qualities of body fluids and blood. Electrolytes are lost primarily through sweat and urine. Excessive loss of water and electrolytes loss can impair heat tolerance, reduce exercise performance and induce severe cramps, exhaustion and stroke.

Stay Balanced

Think of electrolytes as conductors of electromagnetic energy flowing through the body. Minerals are difficult to obtain and many athletes are either deficient in potassium and magnesium or consume inadequate quantities in relation to demand. This can lead to symptoms such as fatigue, impaired glucose metabolism, muscle weakness, cramping and twitching.

The body can regulate the acid/base balance by keeping excess hydrogen ion concentration low and ensuring that normal cell metabolism continues to generate acidic waste. All body fluids contain chemical buffer systems such as bicarbonate, phosphate, protein, hemoglobin and an alkaline reserve. These substances also help maintain acid-base balance, and when stressed, are supported through respiration and kidney function.

Strenuous exercise leads to a temporary state of acidosis, caused mainly from increased carbon dioxide and the formation of lactic acid. As blood lactate concentration increases, pH can drop to as low as 6.8 in the blood, and in active muscle, to 6.4 or lower. At a pH below seven, athletes may experience nausea, headache, dizziness and muscle pain.

A recent article published in Medicine & Science describes how a group of scientists from the Department of Sports Science, Loughborough University, United Kingdom, examined the effects of ingesting a carbohydrate-electrolyte solution on athletes (versus a placebo) on muscle glycogen utilization during 90 minutes of intermittent high-intensity running. The main finding of this study was that the amount of glycogen in muscle used during exercise was reduced by 22 percent when a carbohydrate-electrolyte solution (6.9 percent carbohydrate) was consumed before and at frequent intervals during activity.

Intermittent high-intensity running involves running and walking at various intensities of effort and typifies the activity pattern of many sports. Consuming a six to eight per cent carbohydrate solution reinforced with electrolytes and vitamin C can extend exercise capacity and delay muscle fatigue. Serum insulin and blood glucose concentration is maintained for longer periods, and blood lactate after 30 minutes of exercise is lower compared to a solution of water only.