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The electrolyte facts and why you need them

May 21, 2018

As trainers we are constantly reminding people to hydrate. I've had several people start asking if they need potassium, or if they should start eating bananas more often. To answer your questions, here is a little information about electrolytes.

Electrolytes are different configurations of salts that either carry a positive or negative charge, much like a battery. For example, your body fluids -- blood, plasma, interstitial fluid (fluid between cells) -- are like seawater and have a high concentration of the electrolyte sodium chloride (table salt, or NaCl). The electrolytes in sodium chloride are:

  • sodium ion (Na+) - positive
  • chloride ion (Cl-) - negative

As for your body, the major electrolytes are as follows:

  • sodium (Na+)
  • potassium (K+)
  • chloride (Cl-)
  • calcium (Ca2+)
  • magnesium (Mg2+)
  • bicarbonate (HCO3-)
  • phosphate (PO42-)
  • sulfate (SO42-)

Electrolytes are important because they are what your cells (especially nerve, heart, muscle) use to maintain voltages across their cell membranes and to carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells. Your kidneys work to keep the electrolyte concentrations in your blood constant despite changes in your body. For example, when you exercise heavily, you lose electrolytes through your skin by sweating, particularly sodium and potassium. These electrolytes must be replaced to keep the electrolyte concentrations of your body fluids constant. Many sports drinks have sodium chloride or potassium chloride added to them to help replenish those lost. However, they also have sugar and flavorings to provide your body with extra energy and to make the drink taste better. In order to avoid artificial flavoring or added sugar of sports drinks food is a great alternative to regain the lost electrolytes.


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